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Proceedings of the Chemical Society. June 1963 |
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Proceedings of the Chemical Society ,
Volume 1,
Issue June,
1963,
Page 157-188
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摘要:
PROCEEDINGS OF THE CHEMICAL SOCIETY JUNE 1963 ONE HUNDRED AND TWENTY-SECOND ANNUAL GENERAL MEETING THE One Hundred and Twenty-second Annual General Meeting was held in the Reardon Smith Lecture Theatre of the National Museum of Wales Park Place Cardiff on Thursday March 28th 1963 at 9.30 a.m. The President Professor J. M. Robertson was in the Chair. The President referred with deep regret to the death on the previous Tuesday of Dr. A. D. Mitchell who had retired as Assistant Editor at the end of 1962 after 36 years’ service to the publications of the Society and to whom it had been intended to make a presentation that morning. The notice convening the meeting having been read Professor A. W. Johnson Honorary Secretary presented the Report of Council.Referring to the continued rise in Fellowship he pointed out that the net growth of 11.9% during the year was the largest for many years. Dealing with publications he referred to the large increase in the number of papers submitted for publication in the Journal which was unlikely to abate and stated that the Editorial staff had been increased to deal with the extra volume of work. He also referred to Dr. Cahn’s appointment as Director of Publications Research to investigate the future trends in the method of presentation of papers. Pro- fessor Johnson said that greater stringency had been exercised in the selection of Communications for Proceedings which had resulted in fewer being pub- lished than in th‘e previous year.He added that details of the Society’s other publications in the Report of Council illustrated the great activity in all fields of publication. In his comments on the other activities of the Society Professor Johnson referred to the much greater use of the photocopying service and the in- creased number of books borrowed during the year reflecting the successful administration of the Library. He remarked briefly on the Research Fund stating that as usual more requests had been received than could be met from the income of the Fund. He recalled that the Robert Robinson Lecture- ship has been founded during the year and the first lecture would be given in Birmingham in 1964; that grants had already been made under the Ethel Behrens Fund.He spoke of the debt the Society 157 owed to the Local Representatives and Liaison Officers whose services were gratefully acknowledged. The President called upon the Honorary Treasurer Dr. J. W. Barrett to present the Financial Report and Accounts. Dealing with the General Purposes Account Dr. Barrett said that the growth in Fellow- ship had produced a larger income but unfortu- nately expenditure was also increasing. Administra- tion costs were rising slowly but the cost per Fellow appeared to be contained. Referring to the Publications Fund Dr. Barrett stated that although the income had riseh costs were increasing faster but because the 1961-62 Jozrrnal was abnormally large the rise was not apparent from the account.Taken over the last two years expendi- ture on the Journal and Proceedings had risen from €68,000 to E88,OOO so that the trend was upward and would continue so. He anticipated a greater number of printed pages during the current year at a greater cost per page. He added that steps must be taken to maintain the Society’s finances and to find a solution to the problems of publication of original research. With regard to the Library Account Dr. Barrett stated that the income was derived from transfers from the General Purposes Account and contribu- tions from the Chemical Council and contributing Societies. He added that capital and maintenance expenditure had climbed over the last five years at almost a 10% compound rate of interest. He con- sidered that the present division of expenditure on the Library could not be allowed to continue as the Society carried a far greater burden than the contributing Societies.The Treasurer described the balance sheet as strong and healthy and considered that the Society was in a strong position to meet commitments. There was therefore no need for alarm but the Society must be conscious of the need to look closely at the future. Dealing with the Investments he stated that the Society had received excellent service from J. Henry Shroder Wagg & Co. Limited and that both the General Purposes and the Trust Funds had increased in value and had produced more income during the year. Finally referring briefly with the day-to-day administration of the Society he stated that internal Staff changes brought about during the year had proved successful and to the advantage of the Fellowship.The President spoke of the expansion of the Fellowship and expressed his appreciation of the work of Local Representatives and Liaison Officers. He added that the Society’s main duty was as a publishing body and the Council was taking very active measures to investigate and deal with the PROCEEDINGS problems of publication looming ahead. He added that he was hopeful that the Society’s accommoda- tion needs would be met some progress having been made during the years and he viewed the future with confidence. He concluded by expressing his personal thanks and those of the Officers to the General Secre- tary and his staff for their work on the Society’s behalf during the past year.The President then moved the adoption of the Report and Accounts. Professor K. W. Sykes seconded the motion and it was approved unani- mously. The President then announced the names of the following new members of Council elected to fill vacancies caused by retirement Vice-presidents who have not Jiled the Ofice of President (Appointments made by the Council) Sir Harry Melville Mr. M. W. Perrin Elected Ordinary Members of Council Constituency I Dr. L. Crombie Professor B. C. L Weedon Constituency II Dr. A. B. Foster Constituency 111 Professor J. Lewis Constituency V Professor P. L. Pauson On the motion of Dr. J.W. Barrett seconded by Dr. J. W. Linnett Messrs. W. B. Keen and Co. Finsbury Circus House London E.C.2 were ap- pointed as auditors of the Society’s Accounts for the year ended September 30th 1963. A vote of thanks to the President Officers Council Committees and Local Representatives for their services during the year was proposed by Mr. E. A. Cooke and carried with acclamation. The President thanked Mr. Cooke for his remarks and declared the formal business of the Annual General Meeting terminated. After an interval the meeting was resumed at 10.30 a.m. when the President presented the Harrison Memorial Prize for 1962 to Dr. A. Carrington in consideration of his contributions to the study of theoretical chemistry especially by virtue of his work on electron-spin resonance.The President then gave his Presidential Address entitled “Contributions of X-Ray Analysis to Natural Product Chemistry.” At the conclusion of the Address a vote of thanks to the President proposed by Professor A. W. Johnson was carried with acclamation. JUNE 1963 159 TILDEN LECTURE* Stereoselectivityin the Reactions of Cyclic Compounds By H. B. HENBEST (QUEEN’S BELFAST, UNIVERSITY N. IRELAND) THISlecture will be chiefly concerned with one aspect of the topic covered by the general title directive effects in additions to substituted cyclic compounds. These properties of cyclic compounds have been studied only recently although directive effects in the addition reactions of some substituted acyclic olefins gave rise to one of the earliest generali- sations in organic chemistry (Markovnikov rule 1870).Additions to cycloalkenes in which a sub- stituent group is in a position remote from the double bond will form the main part of this Lecture. Finally some reactions of similarly substituted saturated and unsaturated cyclic ketones will be discussed. When the addition reactions of substituted and unsubstituted cycloalkenes in general are considered we see that the factors governing the production of structural isomers and stereoisomers can be divided into two classes those that are special to ring systems and those that are also apparent in the reactions of acyclic olefins. Reactions covered by the Markovnikov rule come for example into the second group.Thus tertiary chlorides are formed by the addition of hydrogen chloride to both cyclic and acyclic trialkylated olefins. In cyclic systems addition of hydrogen chloride can give the same product starting from an endo- or an exo-cyclic oleffn; the direction of addition is also independent of ring size. In the hydroboronation of acyclic and cyclic tri- substituted olefins the isomers formed predominantly are those in which the boron group is attached to the secondary carbon MeCMe -2% II MeCH -98% By contrast one or two methyl groups at the allylic position in cyclohexene have virtually no effect on the direction of hydroboronation for example equal amounts of 2,2-dimethyl- and 3,3-dimethyl-cyclo- hexanol are obtained starting from 3,3-dimethyl- cyc1ohexene.l The formation of geometrical isomers in additions to cycloalkenes poses two questions (a) is there cis or trans addition of the reagent to the double bond and (b)is this affected by a substituent on the ring? Many stereoselective reactions of olefins (cyclic and acyclic) come under (a) for example cis-hydroxyla- tion via the addition of osmium tetroxide and the cis-addition of boron hydride that occurs in hydro- boronation Specific trans-addition is well illustrated by the formation of diaxial compounds from suitable cyclo- hexenes and halogens.The illustrated reaction of 3-methylcyclohexene with iodine 3,s-dinitrobenzoate provides a more complex example of trans-addition all four geometrical isomers are produced but in unequal proportions.2 ....I 60-c0.R 6I O/o 19% --t + 3O/O (R =3,5-Dinitrophenyl) Question (b) above may be symbolised as in schemes (A) and (B).If the substituent Z is without influence upon the reaction a 50:50 mixture of cis-and tram-product will be obtained. A difference from this ratio is a measure of the directive effect of Z.3 The most readily available substituted cycloalkenes * Delivered before The Society at the University Oxford on February 12th 1962; at the University Bristol on February 13th; at Imperial College London on May 10th; and at the University Southampton on May llth 1962. Brown “Hydroboration,” Benjamin Inc. New York 1962. Lemiewc and Kavadias unpublished work.We thank Professor R. U. Lemieux for this example. Cf. Henbest Nicholls Jackson Wilson Crossley Meyers and McElhinney Bull. Sac. chim. France 1960 1365. PROCEEDINGS for the study of such directive effects are 4-substituted cyclohexenes (e.g. I) and a-and /%substituted bicyclo[2,2,1 Jheptenes (e.g. 11; exo and endo). Although some reactions of these compounds have been investigated the structures of the molecules are not suitable for definitive work on the directive effect of a substituent upon addition reactions. H Results from 4-cyanocyclohexene are bedevilled by the fact that this molecule is flexible; the nitrile group can be in an equatorial or an axial conformation during a reaction (cf. I eq and I ax). The bicyclo- heptenes (11; exo and endo) have a different dis- advantage.In the parent hydrocarbon (111) reagents are known4 to have a strong preference for approach to the /?-face presumably because of the hindrance towards a-face attack imposed by the hydrogens marked H in (111). An a-directive effect due to the nitrile group in the reactions of the substituted com- pounds (11; ex0 and endo) would need to be very strong in order to overcome the normal preference for the formation of /?-orientated products. 4-Substituted cyclopentenes (e.g. IV) are much more suitable compounds; in each there is a plane of symmetry through the substituent and the centre of the double bond and there can be no directive effect other than that caused by the substituent.4-Methylcyclopentene (IV) was synthesised5 in order to find out if a methyl group at a homoallylic posi- tion would afford a directive effect (probably steric). Its reaction with peroxylauric acid gave more trans- than cis-epoxy-compound. Change of solvent (from cyclopentane to acetonitrile) did not change the cis trans product ratio suggesting that the alkyl group was exerting a steric and not a polar effect (see below). 4-Methylcyclopentene is a simple counter- part of steroidal olefins where axial ,&methyl groups in angular positions cause reagents to react at the a-face of the molecule; for example cholest-2-ene in reaction with a peroxy-acid gives at least 85% of the 2a,3 a-epoxide. A steric directive effect is also presumably involved in the reaction of 4-methylcyclopentene with di- borane from which a 75% yield of trans-3-methyl- cyclopentanol is obtained after oxidation of the intermediate organoborane Similarly hydroboronation of cholest-2-ene affords a preponderance of a-alcohols (cholestan-3 a-01 45 %; cholestan-2a-ol 23 %) although cholestan- 3/3-01 (20 %) is also produced.6 Initial carbon-to- boron bond formation at a point farthest from the lO/?-methyl group is involved in the production of the 3 a-alcohol.Addition of acetyl hypobromite to 4-methylcyclo- pentene is also stereoselective. Treatment of the total product with alkali gave the cis-methyl epoxide (VI) in good yield showing that the bromoacetate (V) had been formed in the initial step.The direction of addition in this case may be caused by steric repulsion between the methyl group and the bromine atom the latter being effectively larger than acetoxyl. (v) (VO Earlier experiments (with steroids see below) had shown that a remote polar substituent could influence the stereochemistry of epoxide formation from ap-unsaturated ketones and alkaline hydrogen peroxide. These observations raised the general question do polar substituents show directive effects across two or more saturated rings in other (perhaps simpler one-step) additions? In order to obtain an unequi- vocal answer for reactions at an isolated double bond the unsaturated nitriles (VII VIII and IX) were ~ynthesised.~ Compounds (VIII) and (IX) have fairly rigid structures owing to the trans-junctions ; the distance between the olefinic bond and the polar group in each molecule can be calculated fairly accurately.As with (VII) differences from a 50:50 product ratio in the reactions of (VIII) and (IX) are a measure of the effect of the remote substituent. The formation of epoxides from these unsaturated nitriles was investigated because the geometrical con- & Walborsky and Loncrini J. Amer. Chem. Soc. 1954,76 5396; Kwart and Vosburgh ibid. p. 5400; Wiberg and Saegebarth ibid. 1957,79,2822; Henbest and Nicholls,J. 1959,221. Henbest and McCulIough Proc. Chem. Sac. 1962 74 and unpublished work. Hassner and Pillar J. Org. Chem. 1962 27 2914. Crossley Darby Henbest McCullough Nicholls and Stewart Tetrahedron Letters 1961 398.JUNE 1963 figuration of the epoxy-nitriles could be determined with certainty by dipole-moment measurements and because the direct reaction with a peroxy-acid pro- ceeds in high yield (> go%) obeys a second-order kinetic law accurately is stereospecific and non-reversible and can be carried out in a variety of organic solvents. Addition of oxygen on the side of the molecule trans to the substituent is predominant in the reactions of the three unsaturated nitriles with peroxy- lauric acid in a hydrocarbon e.g. cyclopentane. The percentage trans-attack is given on the following diagrams which are simplified side elevations of the molecules (VII) (VIII) and (IX) CN CN CN Peroxylauric acid 1 < in cyclopentane $5 69 H The &:trans product ratios in the mono- and bi- cyclic series were determined by gas-liquid chroma- tography and are accurate to ca.1 %. The isomeric products from the tricyclic unsaturated &rile were separated by adsorption chromatography and the ratio here is less accurate (ca. 3%); the trans-directive effect of the nitrile group is only just discernible across three rings. This trans-directive effect may be polar or steric in origin. The ratios are dependent on the polarity of the solvent a strong indication that the directive effect is polar. (It will be recalled that the ratio of the cis-and trans-epoxy-compounds from 4-methyl-cyclopentene is independent of solvent.) In aceto- nitrile almost random attack of peroxy-acid occurs with the bi- and tri-cyclic compounds but the mono- cyclic 4-~yanocyclopentene still gives more trans- (76 %) than cis-compound Peroxylauric acid in acetonitrile I <cN I -I-< CN -1- I-\ CN / $6 24 $6 The possibility that the directive effect of the nitrile substituent results from dipole-dipole interaction between it and the transition state of the olefin- peroxy-acid reaction receives support from the fact that the extent of trans-attack depends on the dipole moment of the remote group.The bicyclic cyanide and chloride and the bicyclic epoxide (epoxy-trans- hexalin) are compared CN CI 1-11 t 69 67 pnitrile 3.70 pchloride 2.05D n Methyl derivatives of the mono-and bi-cyclic nitriles (VII and VIII) were prepared in order to evaluate possible steric effects.As expected in the monocyclic series a methyl group decreased the amount of reaction trans to the nitrile group and an isopropyl group had an even larger effect. CN CN Peroxylauric acid in acetonitrile Peroxylauric acid I-<'" li" 8li" l3 J6 H Me CHMe Similar methylation of the bicyclic unsaturated nitrile followed by reaction with the peroxy-acid gave an increased proportion of trans-compound compared with the reaction of the unmethylated starting material. Thus in contrast with the mono- cyclic series there is more attack cis to the alkyl group in the bicyclic compound CN CN Peroxylauric acid I-< -I-< in cyclopentane 1-1 t t Me 69 72 This small but real effect of the methyl substituent may be due to one or both of two reasons (a) the dipole moment of the remote group may be larger [adjacent alkylation increases the moment of a nitrile group acetonitrile (3.48~ propionitrile (3.57~,isobutyronitrile (3.61~)]; (b) the larger methyl group will for conformational reasons in- crease the angle between the nitrile group and the general plane of the ring system.(Calculations con- firm that the polar directive effect of the nitrile group will increase if it moves towards a more perpendi- cular position.) The dipole moments of the products are in line with both of these possibilities:8 We thank Mr. R. J. Bishop and Dr. L. E. Sutton (Oxford) for these values. 162 0 CN ‘‘Ne,”Zrial ’91 HO 4.78D 2.490 0 CN \I< / 1 i C N (CN more “axial”) Me 0 Me 5.05D 1-98D The magnitudes of the cis and trans dipole-dipole interactions in the reactions will depend on the moments of each polar substituent and transition state the distances and angles between them and the dielectric of the intervening medium.Some of these factors can be estimated more accurately than others. By making reasonable assumptions fairly good agree- ment between experimental and calculated values can be obtained. The following simplified expression can be used to examine the distance factor AUm x rm3 = Aub x rb3 = AUt x rt3. A U is the potential energy difference for cis and trans reaction for mono(m)- bi(b)- and tri(t)-cyclic com- pounds and r is the distance between each pair of dipoles (average of cis- and trans-distances).The experimental ratio for the bicyclic nitrile (69 :31 in cyclopentane) gives a A ub value of 480 cal. mole-l which can be used to give calculated values of A Urn and AUt Calculated Experimental A um 2260 1750 (k50) A ut 160 165 (& 75) Dipole-dipole interactions should be increased by replacement of the two olefinic hydrogens by methyl groups as a larger positive charge may then be sup- ported in the vicinity of the ring-carbon atoms; the dipole moment of the transition state should be in- creased and the cis trans product ratio magnified. This effect was observed when cyclopentane (but not acetonitrile) was used as reaction solvent for the following bicyclic compounds trans-Reaction (%) Peroxylauric acid in cyclopentane 74 69 Peroxylauric acid in acetonitrile 54 54 A more extensive survey (see Table) of solvent effects was made in the case of the reaction of 4-cyanocyclohexene (I) with peroxylauric acid.g Henbest and Stewart unpublished results.PROCEEDINGS trans-Epoxy-nitrile ( from 4-cyanocyclohexene in the solvents named Hydrocarbons Halides Cyclopentane Benzene Ethers 82 81 1-Chloropropane 2-Chloropropane Ketones 80 79 Isopropyl ether Diethyl ether Tetrahydrofuran Alcohols 82 80 79 Cyclohexanone but an-2-one Acetone Nitriles 75 75 74 t-Bu tanol Butan-2-01 80 80 Isobutyronitrile Acetonitrile 69 68 Propan-2-01 Cyclohexanol 79.5 79 Nitroalkane Ethylene glycol Methanol 79 78 Nitromethane 69 Ethanol 78 Butan- 1-01 78 The amount of trans-product is greatest in the least polar solvents but closer examination shows that the values do not depend only on the bulk dielectric constant of the solvent or on the dipole moments of individual solvent molecules (e.g.reactions in cyclo- pentane and isopropyl ether afford the same ratio); specific solvation factors are undoubtedly also in- volved. The accessibility of a polar atom or group in the solvent molecules may be a factor of some im- portance (cf. the values obtained in the three ethers). As noted already epoxides can be prepared by reaction of an olefin with acetyl hypobromite followed by treatment of the bromoacetate with alkali OAc 0 \/ I1 /\ c=c -+ -c-c-+ -c-C-/ \ AcOBr I 1 OH-1 I Br In cyclic compounds the configuration of the epoxide is the same as that of the acetate group in its pre- cursor.In order to find the effect of a remote polar substituent on the initial addition the bicyclic nitrile (VIII) was treated with various acyl hypohalites R-CO-CN Vlll I ‘*CN H JUNE 1963 163 -(generated from the appropriate silver salt and halogen in carbon tetrachloride). The total products were treated with alkali and analysed by gas chromatography. AcOCl AcOBr F,C.CO.OBr AcOI F,C.CO-OI trans-Epoxide 1%) 31 38* 45 47* 59 * See text. Change of solvent from carbon tetrachloride to acetonitrile in the reactions marked with an asterisk changes the ratio to 50:50 indicating that a polar directive effect is also operative in these additions.' Although less is known about the mechanism of the olefin-acyl hypohalite reaction the picture (C) of two of the transition states may be proposed.The reactions depicted are those in which the strongest directive effects were observed. The + and -charges are placed on the transition- state side of each diagram so that dipole-dipole interactions with the nitrile group are most favour- able. In the formation of these major products acetoxyl and iodine assume positive charges whereas trifluoroacetoxyl and chlorine more readily assume negative charges. Precedents for such trends are available for more ionic forms of these atoms and groups.In the addition of acetyl hypobromite to mono- cyclic compounds this polar directive effect is opposed by a steric effect; a methyl group and to a greater extent an isopropyl group diminish the proportion of bromine attack on that side of the molecule. CN CN CN (Br) 86.5t 14 (Br) 34.5 'Me (Br) 9 CHMe Directive effects of another kind may be caused by association of the reagent with the substituent by some form of partial bonding. The reagent would then be held albeit temporarily on the same side of the ring as the substituent and the probability of cis- attack could be increased. Such an effect was first observed in the reactions of certain allylic cyclohex- 2-enols with peroxy-acids in which cis-hydroxy-epoxides are formed; hydrogen bonding between the hydroxyl substituent and the reagent was postulated as occurring in these reactions.1° cis-Attack of peroxyacid was also encountered with the allylic amide 3-ben~amidocyclohexene.~~ The predominant formation of trans-epoxy-compounds from allylic ethers and esters and the large negative entropy of activation (see Table) in the cyclohex-2-enol-peroxy- benzoic acid reaction,12 are consistent with the chelative mechanism proposed for the latter.Reactions of peroxy- AH$ Ass. benzoic acid with (kcal. mole-l) (cal. deg.-l mole-l) cyclohexene 10.42 -32.9 3-hydroxycyclohexene 8.35 -41.0 3-methoxycyclohexene 12-36 -30.7 A cis-epoxy-alcohol can also be obtained in high yield (80-90%) from the reaction of a peroxy-acid with the homoallylic cyclopent-3-en01 (X; R = H).The hydroxyl group in this compound is well placed to participate in the transition state of the cis-reaction (cf. XI).13 The yield of cis-product (see Table) is good when cyclopentane or acetonitrile is used as reaction solvent but in ether or propan-2-01 a higher proportion of trans-epoxy-alcohol is produced prob- ably because the hydroxyl group of the unsaturated trons-Epoxy-compound (%) Solvent R=H R=Me Cyclopen t ane 10 92 Acetoni trile 21 67 Diethyl ether 37 91 Methanol 57 57 alcohol tends to be hydrogen bonded to the oxy- genated solvent instead of to the peroxy-acid. The chelative mechanism cannot operate in the reaction of 4-methoxycyclopentene (X; R = Me) with peroxy- acid.In this case the general polar directive effect causes the trans-epoxy-compound to be formed pre- dominantly and the dependence of cis:trans ratio upon solvent is similar to that for 4-cyanocyclo- pentene. lo Henbest and Wilson J. 1957 1958. l1 Goodman Winstein and Boschan J. Amer. Chem. Soc. 1958 80 4312. l2 Henbest and Nicholls unpublished results. l3 Darby Henbest and McClenaghan Chem. and Ind. 1962,462. 164 Other cis-directive effects that depend upon special interactions between reagents and functional groups may be expected. The specific addition of a methylene unit cis to the hydroxyl group of 4-hydroxycyclo- pentene appears to be an example;14 co-ordination of the hydroxyl group to an intermediate organo- metallic species is possible during the addition.Another instance is the cis-attack of peroxy-acid on the anhydride15 (XII). We have confirmed this (XIII) result and have shown that 90% or more of the cis-epoxide is formed in benzene acetonitrile or chloro- form. In contrast the related diester gives the trans-epoxide (XIII) as the main product (80% in cyclo- hexane and 73 % in acetonitrile). Intermediate addi- tion of the peroxy-acid to one of the carbonyl groups of the anhydride (XII) could be responsible for the observed &-selectivity. Remotely placed substituents can also influence the direction of addition of reagents to exocyclic double bonds including that of a keto-group.16 Most information is available in the cyclohexane series where the reactions of alkyl-substituted com- pounds should be first considered.17 The major pro- duct from the reduction of alkylcyclohexanones by metal hydrides in solution is usually the more stable (equatorial) alcohol formed by addition of hydrogen from the axial direction.(Axial addition (Equatorial addition of hydrogen) of hydrogen) LiAlH 92 a NaBH a9 11 Equilibrium ratio 79 21 The results given above for the conformationally rigid 4-t-butylcyclohexanone show that the yield of PROCEEDINGS equatorial alcohol can be higher than that present in the equilibrium mixture of alcohols. Thermodynamic control by the 0-aluminium or 0-boron complex formed in the reaction accounts for this difference; indeed when a mixture of lithium aluminium hydride and aluminium chloride is used for reduction the final yield of equatorial alcohol can be virtually quantitative owing to the exceptionally bulky -0AlC1 intermediate.l8 Another factor that may help to decide the direc- tion of addition to an exocyclic bond of a cyclohexane derivative in its chair conformation is that the two sides of the ring are topologically different and can therefore present different degrees of steric hindrance to an approaching reagent.For this reason a large reagent would be more likely to add from an equa- torial than an axial direction. The addition of osmium tetroxide to 4-t-butylmethylenecyclohexaneis a good example:the diol (XIV) is formed in 90% yield (after hydrolysis of the intermediate adduct).lB Hydrogena- tion catalysts are also bulky and a preference for equatorial approach is often observed although the c ratios obtained can be dependent on other factors e.g.the pressure of hydrogen.20,21 In cases of 4-t-but ylcyclohexanone and 4-t- but ylme t hylenecyclo- hexane the products obtained by addition of hydro- gen from an equatorial direction are known to be the less stable isomers. On the other hand a peroxy-acid is relatively small and the reaction of peroxylauric acid with 4-t-butylmethylenecyclohexane gives mainly the product of axial attack.22 This reaction may be con- 85'10 1570 trolled by steric or thermodynamic factors (or both). With regard to the latter the chief product would also be expected to be the more stable isomer.This l4 Winstein and Sonnenburg J. Amer. Chem. SOC.,1961 83 3235. l5 Gray Heitmeier and Kraus J. Amer. Chem. SOC.,1962 84 89. l6 Combe and Henbest Tetrahedron Letters 1961 404. l7 Dauben Fonken and Noyce J. Amer. Chem. Soc. 1956,78,2579; Dauben and Bozak J. Org. Chem. 1959,24, 1596; Jones and Wise J. Amer. Chem. Soc. 1962,84,997. l8 Eliel and Rerick J. Amer. Chem. SOC.,1960 82 1367. l9 Cross and Whitham unpublished results. We thank Dr. G. H. Whitham (Birmingham) for this information. 2o Eliel and Ro J. Amer. Chem. Soc. 1957,79 5997. 21 Communication from S. Siegel quoted by Sauvage Baker and Hussey J. Amer. Chem. Soc. 1960,82,6090. z2 Henbest and McKervey unpublished results. JUNE 1963 may be suggested from a knowledge of A values of groups (methyl 1.74; hydroxyl O-7Qz3 with structures similar to those of the methylene and epoxide functions.Compared with the behaviour of a 4-alkylcyclo-hexanone reduction of 4-chlorocyclohexanone with sodium borohydride yields a greater proportion of cis-compound:16 'OH 'H (XV) ow Ogl (;;I) NaBH in methanol NaBH in propan-2-01 37 63 Equilibrium ratio 55 45 The formation of more axial alcohol from the chloro- ketone can be explained by dipole-dipole inter- actions between the C-Cl group and the transition state for hydride addition.16 Fhe unusually high proportion (45 %) of cis-isomer in the equilibrium mixture of the chloro-alcohols shows that dipole- dipole interactions are also present in the ground states of these molecules.] This conclusion is sup- ported by study of the kinetics of the reduction of various 4-substituted cyclohexanones because a linear free-energy relation is found when log (reaction rate) is plotted against the a value of the 4-sub- stituent.The increased preference for the formation of cis-product when an electron-attracting substitu- ent is present is reflected in the pcisand ptransvalues (3.78 and 1.96 respecti~ely).~~ This effect of chlorine upon the borohydride R R = H R = m-CI R = P-Cl yo12~~-Alcohol (-& 3%) NaBH in tetrahydrofuran 22 33 29 NaBH in acetonitrile 9 12 17 reduction of a ketone can be transmitted across three saturated rings ;the proportion of 12a(axial)-alcohol from a 12-oxotigogenin is increased when a halogen atom is present at position 3 (see Table).From the quantitative point of view even stronger long-range I65 directive effects are observed in the reactions of 17- substituted 3-oxo-d4-steroids with alkaline hydrogen peroxide.% The f?-epoxide is the normal product but up to 30% of the a-epoxide is formed when an R a-Epoxide (yo)6-Epoxide (yo) H or atkyl 0 100 JS-AC 26 74 H CU-0 27 73 /3-0H 30 70 electron-at tract ing subs t i tuen t is present at posit ion 17. A significant result is that the ratio a:/?-epoxide is changed only slightly when the configuration of the 17-substituent is reversed (it may be noted that 3 a-and 3f?-chlorine both have the effect of increasing the.proportion of 12a-alcohol obtained in the reduc- tion of 12-oxotigogenins).These results suggest that the positive end of the dipole (6+ at C-17) is respon- sible for the directive effect the substituent (the negative end of the dipole) being embedded in the polar solvent and therefore relatively ineffective. The directive effect then depends upon the relative sizes of the electrostatic interactions between the partial positive charge at C-17 and the two anionic reaction intermediates formed by initial a-or f?-addition of hydroperoxide anion at position 5. As the charges in each pair are unlike favourable interactions may develop in both cases but in the intermediate from /?-additionof hydroperoxide ion the steroid molecule is bent which allows polar solvent molecules to inter- pose themselves partially between the line of charges; this does not occur with the more planar intermediate from a-addition of hydroperoxide ion.Numerous possibilities remain for the further investigation of the influence of near and remote groups upon the reactions of alicyclic molecules. A greater variety of directive effects may be found in the reactions of these molecules than in the substitu- tion of aromatic compounds. Already we see that steric factors in addition can be studied with the aid of 4-methylcyclopentene and that the reactions of rigid bicyclic molecules such as (VIII) provide insight into the polarity of certain transition states. 23 Lewisl and Winstein J. Amer. Chem. SOC.,1962 84,2464.24 Kwart and Takeshita J. Amer. Chem. Soc. 1962 84,2833. Q5 Henbest and Jackson unpublished results. PROCEEDINGS COMMUNICATIONS A Stereospecific Synthesis of the Enantiomer of Natural Iridodial and of Natural Nepetalactone By S. A. ACHMAD and G. W. K. CAVILL (SCHOOL THE UNIVERSITY AUSTRALIA) OF CHEMISTRY OF NEW SOUTH WALES ~~LZTZS-PULEGENIC ACID (11) the starting material for these syntheses results from the action of sodium methoxide in methanol) or in dimethoxyethane,2* on pulegone dibromide which in turn is formed from (+)-pulegone (I).394t Treatment of the trans-acid (11) with l0N-hydrochloric acid in methanol gives the 7-lactone (111; 90%) which is then trans- formed into the bicyclo-octenone (IV; 28%) by the action of phosphorus pentoxide in phosphoric acid.Use of the bicyclo-octenone (IV) as an intermediate in the synthesis of two cyclopentanoid monoterpenes5 (vta) ;R-H is now described. (Vlb) ;R=Ac \ Epoxidation of (IV) with alkaline hydrogen per- oxide solution gives the 0x0-epoxide (V; 52%) which is converted into the hydroxybicyclo-octenone I (VIa; 80%) by sulphuric acid in acetic acid. Com- plete hydrogenation (Adams catalyst) of its acetate (VIb; 89%) yields the diol monoacetate (98%), which is assigned structure (VIIa). Hydrolysis of (VIIa) gives the crystalline diol (VIIb; 89 %). Finally (Vila); R-AC fission of this diol with sodium periodate in aqueous (Vllb) ; R-H ethanol yields (VIII) the enantiomer of one of the forms of natural iridodial.6 Gas chromatography of c (VIII) gives one peak whereas natural iridodial shows two peaks.Synthetic iridodial (VIII) after treatment with aqueous acetic acid gives a product whose gas-chromatographic retention times and infrared spectrum are in agreement with those of the natural product. Peracid oxidation of the bicyclo-octenone (IV) should give the nepetalactone (XI) but this direct red spectrum of (XI) corresponds closely to that of transformation has not yet been achieved. Alterna- natural nepetalactone which contains E XI and a tively partial hydrogenation (Adams catalyst) of proportion of E MI.' Conversion of synthetic (VIb) gives the saturated acetoxy-ketone (IXa; 85 %) nepetalactone (XI) into the nepetalinic acids of whence alkaline hydrolysis yields the parent ketol known configuration is in progress.(1%; 73%). Oxidation of this ketol with lead tetra- acetate in acetic acid gives the nepetalic acids (as X) The authors acknowledge the award of a Colombo which on pyrolysis are converted into the enantio- Plan Scholarship (to S.A.A.) and thank Dr. E. J. mer of natural nepetalactone (XI; 63%). Gas Eisenbraun for a specimen of natural nepetalactone. chromatography shows one peak identical in reten- tion time with that of the natural product. The infra- (Received April lst 1963.) * We agree with Wolinsky Wolf. and Gibson' on the stereochemistry of the pulegenic acids but disagree with their interpretation of the Favorskii transformationsa which are involved. 7 (+)-Pulegone as supplied by Keith Harris and Co.Ltd. Sydney has [ a] + 24-1'. Wolinsky Wolf and Gibson J. Org. Chem. 1963 28,274. Achmad and Cavill unpublished work. Wallach Annalen 1917 414 233 and earlier papers. von Rupe and Schafer Helv. Chim. Ada 1928 11,466. For a review see Cavill Rev. Pure and Appl. Chem. 1960 10 169. Cavill and Ford Austral. J. Chem. 1960 13 296. Bates Eisenbraun and McElvain J. Amer. Chem. Suc. 1958,80 3420 and earlier papers. JUNE 1963 167 Study of Organic Molecular Complexes by Polarography By M. E. PEOVER (NATIONAL LABORATORY MIDDLESEX) CHEMICAL TEDDINGTON SOME of the first determinations of the stabilities of organic complexes were made in the course of aqueous potentiometric titrations of redox systems in which dimers are formed between the reduced and the oxidised species.l However such systems con- stitute special examples of a much wider group of donor-acceptor interactions “charge-transfer” in- terations.2 Under polarographic conditions in aprotic sol-vents of moderate dielectric constant most aromatic acceptor molecules have been found to exhibit reversible oxidation-reduction behaviour? A + e +A-.We find this is also true in some solvents of low dielectric constant (chloroform methylene chloride benzotrifluoride tetrahydrofuran) in which donor-acceptor interactions tend to be strongest. In the presence of a compound forming a complex with A but not with A- the polarography of the A +A-system should be altered in a manner which depends on the free-energy of formation of the donor-acceptor complex.We find that organic donor- acceptor interactions are readily studied in this way. Special problems of technique encountered are a high concentration of supporting electrolyte is required to eliminate migration currents (0.5~-NBu,ClO is satisfactory); a high cell resistance which was overcome by using a controlled-potential device;4 a suitable reference electrode for which the half-cell Ag IAgI AgI(sat.) O-O~M-NBU,~ 0.5~- NBu,C104 in the chosen solvent was found satis- factory; and occasional adsorption phenomena usually eliminated by a trace of a polymer. Adding hexamethylbenzene to a chloroform solu- tion of say tetracyanoethylene shifts the first wave in the polarogram of the latter to more negative potentials (e.g.a shift of 50 mv is obtained with 0-55h.r-hexamethylbenzene);the polarogram remains reversible indicating rapid dissociation of the com- plex that is confirmed by as. polarograms. The shifts in half-wave potential d,from the value in the absence of added hexamethylbenzene can be analysed by conventional metal-ion ligand theory :5 of simple and complex species at the donor con- centration [D] ([D] B [A]). Plots of Fl= (Fo-l)/ [D] against [D] are shown for a number of acceptor molecules. The plots giving lines parallel to the x-axis indicate 1 :1 association with y-intercepts of Kl. The dichlorodicyanoquinone plot shows that association with two hexamethylbenzene molecules occurs; the intercept gives K, the slope Kz.The Klvalues are lower than are obtained from observations on the charge-transfer bands in pure chloroform.Probably the supporting electrolyte ion-pairs have the same effect as adding a small quantity of polar solvent. The polarographic method assumes that the donor con- centration at the surface of the electrode is the same as in the bulk of the solution and that there is no influence from the electric field in the vicinity of the electrode. n n -bn w -0 V 5-n n a, \J W I I I I I 0.2 09 103 (mole I?) Complex formation as a function of hexamethyl-benzene concentration with (a) tetracyanoquinodi-methane (b) chloranil (c) tetracyanoethylene (d) 2,3-dic121oro-5,6-dicyanoquinone,in CHC~,-@~N-NBu4C10, at 25”.Acceptor concn. 5 -8 X 10+~. I Fo = antiloglo 2.303RT ~ FA = 1 + Kl[D] + K2[DI24-.. . K,lr>ln IC in which Kl,K2.. . are successive formation con- Studies in chloroform solution are limited to the stants and I,/Ic is the ratio of the diffusion current stronger acceptor molecules because of reduction of Michaelis and Fletcher J. Amer. Chern. SOC.,1937 59 2460; Michaelis and Schubert Chem. Rev. 1938 22 437. Mulliken J. Chem. Phys. 1951 19 514. Peover Nature 1961 191 702; Trans. Faraday SOC.,1962 58 1656 2370. Arthur and Vanderkam Analyt. Chem. 1961 33 765. See Irving Adv. Polarography 1960 42. PROCEEDINGS the solvent at negative potentials; most acceptors graphic method allows a precise study of the can be studied in methylene chloride.If the acceptor energetics of these various processes. Other ad-does not give a reversible reduction wave the donor vantages are (i) the method is independent of the component may undergo reversible oxidation (e.g. assumptions of the spectroscopic method (ii) it is tetramethyl-p-phenylenediamine).When the half-applicable where charge-transfer absorptions are wave potentials of donor and acceptor are similar a concealed or ambiguous and (iii) interaction with redox process giving free-radical ion formation transient species capable of electrochemical genera- occurs6 as well as complex formation. The polaro- tion can be studied. (Received Apd 6th 1963.) Briegleb “Elektronen-Donator-Acceptor-Komplexe,” Springer-Verlag Berlin 1962 p. 186; Allison Peover and Gough Nature 1963 197 764.Biosynthesis in the Amaryllidaceae Further Evidence on the C6-cI Unit and the Methylenedioxy-group By D. A. ARCHER R. BINKS A. R. BATTERSBY, S. W. BREUER and W. C. WILDMAN (THE ROBERT LABORATORIES AM) THE DEPARTMENTS ROBINSON UNIVERSITY OF LIVERPOOL OF CHEMISTRY OF BRISTOL STATE UNIVERSITY AND IOWA UNIVERSITY) THEconversion of phenylalanine into the c&1 unit MeOA which is built into belladinel (I) and lycorine1y2 01) may occur (a) via phenylserine and then fission2 or (b) by way of cinnamic acid1 as for the phenolic cinnamic acids.3 The tracer evidence below supports the latter pathway. Sodium trans-[3-14C]cinnamate fed to Nerine bowdenii plants yielded radioactive alkaloids. The lycorine (11; 1.00 C* incorporation 0.02%) was oxidised and the product isolated as N-methyl-hydrastimide4 (111; 0-97 C*).Degradation of the belladine (I; 1-00 C*) as earlier proved that ring A and atom Clt together carry almost all (0.94 C*) of R‘ the total activity of the molecule. Sprekelia formosissima plants were fed with .a& HO \ [7-14C]benzaldehyde; the isolated tazettine (IV) was weakly radioactive (0.005 % incorporation). De- R\ H gradation5 to NN-dimethylglycine showed 5 % of the (v) total activity in this unit. This result and the poor lation occurs at a later stage in the biosynthesis and incorporation compared with other precursors5 sug- experiments to test this are in hand. gest that benzaldehyde is not on the biosynthetic The methylene group of the methylenedioxy-pathway.Also [l‘-14C]bisdeoxynorbeelladine(V; R system of haemanthamine has been proved’ to = R’ = H) fed to the same species led to tazettine originate from an 0-methyl group. Support for this (IV) and haemanthamine of negligible activity. origin in the case of lycorine has been obtained by to “Twink” daffo- The stage at which introduction of the hydroxyl feeding L-[met?~yl-~~C]methionine~ group at position-2 of lycorine occurs has been dils. The isolated lycorine (11) and norpluviine (VI) studied by feeding [1’-14C]hydroxynorbelladine(V ; were labelled almost exclusively at the methylene R = R’ = OH) to “Twink” double Narcissus plants. group (0-95 C*) and at the 0-methyl group (1.01 C*) The incorporations into lycorine (11) and norpluviine respectively.(VI) were 6-23 x lo4% and 1.7 x respec-This investigation was supported in part by a tively; the incorporations6 from norbelladine (V; R Public Health Service Research Grant to Iowa State = OH R’ = €4) into these alkaloids were 0.24% University of Science and Technology from the and 0.74% respectively. This suggests that hydroxy- National Heart Institute. (Received April 26th 1963.) Wildman Battersby and Breuer J. Amer. Chem. Soc. 1962 84,4599. Suhadolnik Fisher and Zulalian J. Amer. Chem. SOC. 1962,84,4348. McCalla and Neish Canad. J. Biochem. and Physiol. 1959 37 537; Neish Phytochem. 1961 1 1. Warnhoff and Wildman J. Amer. Chem. SOC. 1957,79,2192. Wildman Fales and Battersby J. Amer. Chem. Soc. 1962 84 681. Battersby Binks Breuer Fales and Wildman Proc.Chern. Soc. 1961 243. Barton Kirby and Taylor Proc. Chem. Sac. 1962 340. Cf. Sribney and Kirkwood Nature 1953 171 931. JUNE 1963 169 The Kinetics of the Dissociation of Weak Acids measured by a Rotating Platinum Disc Electrode By W. J. ALBERY and R. P. BELL (PHYSICAL LABORATORY, CHEMISTRY OXFORD) THE kinetics of the fast forward and backward reactions of an equilibrium between reducible and irreducible species in solution have been widely studied by polarography. It has been known for some time that similar studies could be carried out with a rotating platinum disc electrode and in fact Vielstich and Jahnl have investigated the dissocia- tion rates of a number of weak acids. The rotating disc electrode has advantages over the mercury drop in that the speed of rotation can be easily varied and accurately measured ; the corres- ponding quantity in polarography the drop time is not such a convenient experimental variable.Further- more platinum has a much lower overvoltage for the discharge of hydrogen than mercury and so reactions involving protons can be studied directly and no de- polariser is needed. But unfortunately when the potential of the rotating electrode is made large enough to make the electrode reaction very much faster than the diffusion of protons to the disc so that the limiting diffusion current can be measured water itself begins to be decomposed on the electrode. This means that one observes only a point of in- flexion in the current-voltage curve rather than a substantial plateau.Calculations of rate constants based on such points of inflexion are likely to have a large error. We have developed a modification of the method which allows the current due to the decomposition of water to be balanced and hence the true limiting current to be measured. Two cells each with a rotating electrode are used. One is filled with a standard hydrochloric acid solution the other with the weak acid buffer to be studied. They are made part of a Wheatstone bridge circuit. The ratio of the values of the two resistances in the other arms of the circuit is the same as the areas of the two discs. This ensures that when the bridge is balanced not only is there the same potential difference at both elec- trodes but also the same current density.Under these conditions the decomposition of water per unit area should be identical on each disc and hence the current due to the electrode reaction Hf + e -+H2 should also be equal. At the potentials used the “water current” is still considerably smaller than the “H+ current” and so the above assumptions need only be a first-order approximation. Vielstich and Jahn 2.Elektrochem. 1960 64 43. Koutecky and Levich Zhur. $2. Klzim. 1958,32 1565. Dogonadse Zhur. fiz. Khim.,1958,32,2437. Gregory and Riddiford J. Cliern. Soc. 1956 3756. To find the balancing conditions the “weak-acid electrode” is rotated at a known speed. A series of voltages are applied across the Wheatstone bridge.At each voltage the speed of the “strong-acid elec- trode” is adjusted until the bridge is balanced. A range of about 0.15 v is found over which this speed alters by less than 2%. This corresponds to the plateau in the normal current-voltage diagram. At this point from previous w~rk~~~~* we find that CH+ Flux = PH+ &JH+ where subscript H+ refers to the strong acid and subscript HA to the weak acid. Also p = 1.8 v- D-8 ( ;)0’36} where D is the diffusion coefficieiit in cm.2 sec.-l v the kinematic viscosity in cm.2 sec.-l C the con- centration,w the velocity of rotation in radians sec.-l k the first-order rate constant for the dissociation HA -+ Hf + A- in sec.-l K the dissociation con- stant for the weak acid in moles 1.-l and [A-] the calculated concentration of weak acid anion at the electrode.Rearranging one gets Since p varies as D-8 and since DH+ -8 x DHA CHAis made about 4 x C,+SO that wH+-wHA. To prevent migration of reactants due to the electric field it is usual to use an excess of an inert salt in the cell. But since the larger the concentration of A- the larger will be the kinetic terms we have used KA only. The excess of salt both carries the current and acts as the buffer. Measurements have been made on solutions con- taining 2 x 10-2M-acetic acid in 0.1~- and in 0.3~-potassium acetate and on 3 x 10-2M-trimethylacetic acid in 0.1111- and in 0*3~-potassium trimethylacetate. The strong-acid solution used throughout was 5 x 10-3~-hydrochloric in 0.lwpotassium chloride. The limiting current of the strong-acid solution by itself agreed with the theoretically calculated current to about 1%. For acetic acid the intercept term (cH+PHA/ c,,p,+) for the plot of 21 (wnA/wH+) against AmHAagreed with theory to within the PROCEEDINGS experimental error of 3 %. The diffusion coefficient kd (sec.-l) k (mole-l 1. sec.-l) of trimethylacetic acid has not yet been measured. Acetic acid 9.1 x 105 5.2 X lOlo An estimate for the intercept based on the relative Trimet hylacetic mobilities of AcO- and Me3CC02- was within 4% acid 1-42 x 105 1.53 x 1O1O of the experimental value for 0.1M-potassium tri- methylacetate. There was a much larger discrepancy The experimental error is estimated at -& 10%.for a 0-3~-solution but in this case the viscosity of The average value for acetic acid agrees well with the solution is 1-15 times that of pure water and so that of Eigen and Eyring which was obtained by a it is likely that the estimated value is in error. relaxation technique the dispersion of an electric field being mea~ured.~ The low value for the recom- The results obtained for kdat 25"c in sec.-l were bination reaction between H+ and Me,CC02- must 9.7 x 105 O.IM-KO,C.CM~ 1.26 x 105 be due to the large steric blocking effect of the t-butyl O-IM-KOAC 7.6 X lo5 O.~M-KO,C.CM~ gfOUP-O*~M-KOAC 1.31 X 105 On correcting for the drop in D+ + 13-caused by One of us (W.J.A.) thanks the Gas Council for a the salt solutions and on averaging one gets the research scholarship.following values at infinite dilution (Received April 5th 1963.) Eigen and Eyring J. Amer. Chern. SOC.,1962,84 3254. The Synthesis of Cycloartane By D. H. R. BARTON COLLEGE, (IMPERIAL LONDON S.W.7) and R. P. BUDHIRAJA and J. F. MCGHIE OF CHEMISTRY COLLEGE AND TECHNOLOGY, (DEPARTMENT CHELSEA OF SCIENCE LONDON s.w.3) WE wish to report the synthesis of cycloartanel (I; [a] + 34" which on chromic acid oxidation R = C,H,, R' = R" = H) the parent hydrocarbon afforded the dione (I; R = C8H1, R' = (:O)) m.p. O, of an expanding group2 of pentacyclic triterpenoids. 168-171 [a],+ 74". Wolf-Kishner reduction of Photolysis3 of the nitrite (11; R = C8H17,R' = the latter under forcing conditions4 gave cycloartane NO R" = Me) m.p.124-127" [a] + 95" of (m.p. mixed m.p. [a], and analysis). 3/%acetoxylanostan- 1 1/3-01 gave the 19-oximino-R derivative (11; R = C8H1, R' = H R" = CH=N-OH) m.p. 199-203" [a],+ 84" together with 3/3-acetoxylanostan-1l/3-oland some 319-acetoxylanostan-1 1-one. There was little if any attack upon C-18. Reduction of the oxime with lithium aluminium hydride gave 19-aminolanostan- 3&11/3-diol m.p. 219-222" [a],+ 46". Dehydra- tion of the oxime with sodium acetate-acetic anhydride on the steam-bath gave the acetoxy- nitrile (II; R = C8H17 R' = H R" = CN) m.p. 259-260" [a],+ 69" which with phosphorus oxy- Since lanosterol from which the 3P-acetoxy-chloride and pyridine afforded the olefin (111; R = lanostan-1 1/3-01 was prepared has been synthesised C8Hl, R' = Ac R" = CN) m.p.151-153" [a] $-51". Reduction of the latter with lithium from cholesterol5 the present work constitutes a aluminium hydride furnished the amine (111; R = (formal) total synthesis of cycloartane. Satisfactory spectral and analytical data have been C8H17 R' = H R" = CH,-NH,) m.p. 243-244" [a] + 75". Deamination with sodium nitrite in obtained for all new compounds. [a] are in dioxan-acetic acid-water gave the diol (I; R = chloroform (approx. 1 %). C,H,, R' = /%OH R" = cuOH) m.p. 171-174" (Received April 1sf 1963.) Barton J. 1951 1444. Djerassi and McCrindie J. 1962 4034; and references there cited. Barton Beaton Geller and Pechet J. Amer. Chem. Soc. 1960 82 2640; 1961 83 4076. Barton Ives and Thomas J.1955 2056. Woodward Patchett Barton Ives and Kelly J. 1957 1131. JUNE 1963 171 Perloline By J. A. D. JEFFREYS and G. A. SIM (THE ROYAL OF SCIENCE AND THE UNIVERSITY COLLEGE AND TECHNOLOGY GLASGOW) R. H. BURNELL and W. I. TAYLOR (RESEARCH CIBA PHARMACEUTICAL DIVISION SUMMIT, DEPARTMENT COMPANY OF CIBA CORPORATION U.S.A. AND THE UNIVERSITY KINGSTON, NEW JERSEY OF THE WESTINDIES JAMAICA) R. E. CORBETT and B. J. SWEETMAN THE LATE J. MURRAY (CHEMISTRY UNIVERSITY DEPARTMENT OF OTAGO,NEW ZEALAND) PERLOLINE the main alkaloid of perennial rye-grass Patterson sections and the lighter atoms (other than (Loliurn perenne L.) and its salts are of the form hydrogen) by three-dimensional Fourier methods CmHl,N20,,X,yH20 ; in the free base perloline from 2077 independent structure-amplitudes.The that crystallises from ethyl cellosolve-water (1 :l) value of R is now 13.9%. X = OH y = 0;in the perchlorate m.p. 280" (de- The HgC12- anion is tetrahedral with an average camp.) Vmax. (C = N+) 1695 cm.-l X = C104 Hg-Cl of distance 2.50 A. The water molecule is y = 1 or 0; in the nitrate m.p. 185-190" (decomp.) independent of the alkaloid cation which is therefore X = NO3 y = 1 or 0;in the mercurichloride (red the protonated form of anhydroperloline and has form) m.p. ca. 210" (effervescence),X = g(HgCI,) structure (I). Perloline then has structure (II) and as y = 1. removal of the dimethoxyphenyl group gives Hydrogenation in acetic acid or reduction by perlolidine Vmax. (N-H) 3148 (C = 0)1665 cm.-l, lithium aluminium hydride in tetrahydrofuran of which also occurs in perennial rye-grass the struc- perloline gave a product C2@H18N203 m.p.220" ture of this alkaloid is defined as (111). In agreement (decomp.) (with an ultraviolet absorption spectrum with the result of the X-ray analysis the nuclear similar to that of dimethylaniline) which was readily magnetic resonance spectrum of anhydroperloline reoxidised to perloline. Acetylation of perloline gave shows the presence of 16 protons 6 of which are in an N-acetyl derivative (formed by acetic anhydride the methoxyl region and the remainder aromatic. in pyridine) m.p. 232" (decomp.) Ymax. (C = 0) 1650 cm.-l (broad) or an 0-acetate (formed in re- fluxing acetic anhydride) m.p.296" (decomp.) vmax. (C = 0)1766 and 1650 cm.-l. The degradation of perloline and its derivatives in various ways to perlolidine C12H,N20 (formula de- fined by nuclear magnetic resonance and mass spectroscopy) is interpreted as removal of a di-methoxyphenyl residue attached to nitrogen since pyrocatechol was obtained on selenium dehydro- genation and pyrocatechol guaiacol and veratrole are obtained on pyrolysis of perloline but oxidation did not yield veratric acid. A by-product in the oxidation of perloline with potassium ferricyanide m.p. 288" (de- This diazaphenanthrene ring system has not was a substance C20H,aN204,2H20 camp.) regarded as the lactam which would result previously been reported in a natural product. The from oxidation of a carbinolamine function.With positions of the nitrogen atoms suggest that a nitric acid both perloline and perlolidine gave picric tryptamine precursor may be involved in the acid diagnostic of a benzene residue. biogenesis. A crystal-structure analysis of the red form of per- Ioline mercurichloride has been carried out at Glas- The extensive calculations were carried out on the gow. The crystals are orthorhombic space group Cilasgow University DEUCE computor with pro- Pnna,with eight sets of C2aH1,N203,~(HgCl,),H20 grammes devised by Drs. J. s. Rollett2 and J. G. in the unit cell of sides a = 12.83 b = 16-63 c = Sime3. We are grateful to Professor J. M. Robertson 18-85 A. The mercury atoms were located from C.B.E. F.R.S. for his interest to Dr. K. Biemann For a summary of the previously published chemistry see T.A. Henry "The Plant Alkaloids," J. and A. Churchilf Ltd. London 1949 p. 749. Rollett in "Computing Methods and the Phase Problem in X-Ray Crystal Analysis," ed. Pepinsky Robertson and Speakman Pergarnon Press Oxford 1961 p. 87. Sirne ref. 2 p. 301. 172 PROCEEDINGS (M.I.T.) for mass spectroscopy and to Dr. A. Melera (Varian A.G. Zurich) for n. m. r. spectro- scopy. Part of this work was commenced during the tenure of an I.C.I. Fellowship Cambridge 1951-52 (W.I.T.) and continued under a Lord Beaverbrook graduate scholarship University of New Brunswick 1952-53 (R.H.B.). (Received February 9th 1963.) Exchange Processes in the Reaction of Boron Tnichloride with Triethylamine-Boron Trifluoride By T.D. COYLE (NATIONAL OF STANDARDS 25 D.C.) BUREAU WASHINGTON ALTHOUGH reactions in which one tervalent boron compound in a Lewis base complex is replaced by a second are well known little information is available on their mechanisms. In the reaction of boron tri- fluoride with the trimethylamine complexes of organoboron dichlorides to give organoboron di- fluorides boron-nitrogen bond cleavage occurs accompanied by halogen transfer. Replacement of boron trifluoride from its trimethylamine complex by boron trichloride is almost quantitative at 205". At this temperature the reaction may involve partial dissociation of the complex followed by rapid inter- In dilution experiments isotopically normal boron trichloride (boron content taken as 20.0% of log) was added to lOB-enriched triethylamine-boron trifluoride (boron content 91.2% of l0B).At the end of the reaction time material volatile at 0" was removed (quantitative recovery based on boron tri- chloride taken). This mixture of halides was kept at room temperature for 1 hr. The trifluoride was separated from the trichloride by repeated vacuum- line fractionation and analysed mass spectro-metrically. Results of two typical experiments are summarised in the Table. Temp. Time (C,H,),N,BF BCl BF,(%) l0B Content (hr.) (mmole) (mmole) in products (x) 0' 4 ' 4.68 60" 16 5.14 action of free trimethylamine with boron trichloride although a bimoIecular displacement of boron ti-i- fluoride by the trichloride at lower temperatures was suggested.2 The reaction3 of amine-boranes with a deficiency of boron trichloride or tribromide to give compounds of the type R1R2R3N,BH,Ha13-% led however to suggestions that this reaction proceeds via hydrogen-halogen exchange without the break- ing of boron-nitrogen bonds.The heterogeneous reaction of boron trichloride with triethylamine-boron trifluoride has now been investigated Et,N,BF + BCl +Et,N,BCl -I-BF,. Isotopic dilution techniques established that the observed replacement involves two distinct pathways. Under sufficiently mild conditions boron trifluoride is formed rapidly without significant B-N bond cleavage while under more vigorous conditions processes involving exchange of boron atoms bonded to the donor atom become important.Triethylamine-boron trifluoride was treated with a slight deficiency of boron trichloride at temperatures between -80" and 60" The change of pressure over the mixture of complex and boron halide and the infrared spectrum of the volatile components showed that free boron trifluoride appears in a few minutes even at -80". 4.50' -64.8 2410 4.99 70.3 57.2 At 0" although 65% "replacement" of boron tri- fluoride was observed the isotopic composition of the trichloride-trifluoride mixture corresponds to exchange with added trichloride of only about 5% of the boron originally in the complex. Formation of boron trifluoride at 0" thus occurs principally with- out cleavage of boron-nitrogen bonds most prob- ably by halogen exchange between ter- and quadri- valent boron.Less exact isotope ratios from the infrared spectrum of the halide mixture obtained by treating isotopically normal triethylamine-boron trichloride with lOB-enriched boron trifluoride at 0" indicate that halogen exchange is the principal process by which boron trichloride is formed in the reverse reaction. At 60" however boron-nitrogen bonds are broken and re-formed and the isotopic composition of the halide mixture obtained is close to that expected (56.0 % of log)for complete isotopic equilibration of the boron in the sample. This could occur either through partial dissociation of the various complexes present and competitive re-asqociation of the components or by a true displace- ment reaction The author thanks Mr.E. E. Hughes for the mass spectrometric analyses. (Received April loth 1963.) Brinckman and Stone J. Amev. Chem. Soc. 1960 82 6235; Brinckman Ph.D. Thesis Harvard University 1960. Dutton Paterson and Onyszchuk Proc. Chem. Soc. 1960 149. Ratajczak Bull. SOC.chim. France 1960,487; Noth and Beyer Chem. Ber. 1960,93,2251. JUNE 1963 173 ~-~ ~~~~~ ~~ ~ Six-co-ordinate Complexes of Bivalent Platinum and Nickel By N. C. STEPHENSON and G. A. JEFFREY (THE CRYSTALLOGRAPHY UNIVERSITY LABORATORY OF PITTSBURGH PITTSBURGH 13 PA. U.S.A.) THE study of diamagnetic ds-complexes was until recently concerned with the investigation of their square-planar four-fold co-ordination. o-Phenylene- bisdimethylarsine (diarsine) forms complexes of bi- valent platinum palladium and nickel which have been shown to exist as five-co-ordinate cations [M1l(diarsine),Halogen]+ in solution1 and six-co- ordinate molecules [M1l(diarsine),l,] in the solid state.3 We have elucidated the complete crystal structures of the complexes (i) Pt(diarsine),Cl and (ii) Ni(diarsine),I,.The crystal data are (i) a = 9-66 b = 16.60 c = 18.02A Z = 4 space group Pcan; (ii) a == 9.49 b = 9.25 c = 16-94A ,8 = 114.0" Z = 2 space group Pz,/c. The cell dimensions were obtained from zero-layer precession and Weissenberg photographs and are accurate to about 0.5 %. Three-diniensional data for each compound were recorded on multifilm Weissenberg photographs and were estimated visually; respectively 1649 and 1688 independent structure amplitudes were determined for the two compounds.by four arsenic atoms in a square plane and two halogens complete the structure which in total is distorted-octahedral. ']The bond lengths and angles are given in the Table. The Ni-As bond distances are significantly shorter than the normal covalent sum (2-57 A) for the two elements (d/a > 30). The Pt-As bond distances are also appreciably shorter than the sum of the square covalent radius €or platinum(n) and the tetrahedral Bond distances (A) and angles. Mean e.s.d. Ni-As 2.28 2.30 2.28 2.30 0.002 AS-CH a 1-92 b 1-87 c 2-01 d 1 -93 0.03 I-CH Ni-As-CH A a 3.78 117.3" Bfl 3.84 120-1" C y 3.87 121.4" D 6 3.74 118-9" 0-03 0-90 Pt-AS 2.38 2.37 2-38 2.37 0.004 AS-CH a 2.05 b 2-04 c 1-91 d 1~87 0.04 Cl-CH Pt-AS-CH A a 4-42 114.1" Bfl 4-16 109.5" C y 4.22 119.1" D 6 4-48 119.3" 0.04 1 *20 Hatched circles = Halogen.Open circles = arsenic. Large filled circles = metal. Small filled circles = methyl. The position of the heavy atoms were obtained from two-dimensional Patterson and Fourier syn- theses. The heavy atoms determined the majority of the structure phases and the carbon atoms were located from three-dimensional difference Fourier syntheses. The refinement of positional and aniso- tropic thermal parameters for all atoms was carried out by means of successive differential syntheses with Shiono's IBM 7070 programme^.^ The final R values are 12% and 1 1 % for the platinum and the nickel compound respectively.The arrangement of the halogen ions and diarsine chelates around the transition metals is shown in the Figure. In both cases the central atom is surrounded covalent radius for arsenic (1.31 + 1-18 = 2-49A). This bond distance is the same as that found2 for the Pt-As bond in the compound Pt(diarsine),I,. The shortening is probably due to interaction between the less stable and unfilled ligand d orbitals and the filled metal d orbitals. In this case the metal d orbitals are stabilised by the interaction and the separation d between fzg and e orbitals is thus increased. The Pt-C1 bond is considered to be ionic. This bond distance (4-16A) exceeds the sum of the ionic radius of chlorine and the van der Waals radius of bivalent platinum (1-81 + 2-07 = 3.88 A).The chloride ion is cushioned on four methyl groups and the approach distances do not indicate a strong inter- l Harris Nyholm and Phillips J. 1960 4379. Harris Nyholm and Stephenson Nature 1956 177 1127. '' Programmes no. 330 and 376 World List of Crystallographic Computer programmes 1961,I.U.Cr. PROCEEDINGS action with the square-planar cations. The estimated significant distortion of the Ni-As-CH angles (CT = standard deviation in the Pt-As-CH angle is 1-2" 0.74") from the tetrahedral value. so that the distortions from the normal tetrahedral angle are significant. This research was aided by a grant from the U.S. The short Ni-I bond distances of 3.21 A and the Army Research Office (Durham).One of us (N.C.S.) close approach of each iodide ion to the four cis- is grateful for leave from the University of New oriented methyl groups suggest a strong interaction South Wales Australia. between nickel and the two iodide ions. There is a (Received March 4th 1963.) Isomerisation of Toiuenesulphonic Acids in Aqueous Sulphuric Acid By A. C. M. WANDERS and H. CERFONTAIN FOR ORGANIC UNIVERSITY THE NETHERLANDS) (LABORATORY CHEMISTRY OF AMSTERDAM publications by Spryskovl on the sulphona- culated as para 37.2 f2.2 % meta 59-6 -& 2-5% and RECENT tion of toluene in concentrated aqueous sulphuric ortho 3-2 & 0.6%. Toluene-m-sulphonic acid is acid at elevated temperatures and prolonged reaction apparently thermodynamically the most and toluene- time prompt us to report a kinetic study of the o-sulphonic acid the least stable isomer.Our results isomerisation of the toluenesulphonic acids in conflict with previous observations3 stating that aqueous sulphuric acid. toluene-p- and -0-sulphonic acid on isomerisation The isomerisations were studied in 74.0 f do not yield any -rn-sulphonic acid. 0.3 wt.-% aqueous sulphuric acid at 140.8" f0.5" The apparent rate constants for isomerisation under homogeneous conditions. The method of determined graphically from initial rate of disap- analysis was similar to that described previously.2 pearance of the parent isomer and from the initial rates Material balances were better than 90%. Toluene- of formation of the other isomers listed in the Apparent isomerisation rate constants (a21 x lo6,sec.-l)* kprn kP0 kmp km0 kOP kom t 13 i2 16 f5 6.7 zt 0.5 0-2 f0.1 320 & 20 40 4 20 + 26 f5 7-1 & 0-8 90 f40 *kt),,,denotes the apparent rate constant para -+meta etc.t Determined from initial rate of formation of the new isomer. t Determined as the difference between the rate constant of disappearance of the parent compound and that of formation of the other isomer. p-and -m-sulphonic acid both isomerise to yield a Table illustrate once more the relative instability of mixture of mostly toluene-rn- and -p-sulphonic acid the ortho-isomer under the reaction conditions used. and kp0/k, calculated from with only a small amount of ortho-isomer. On iso-The values of kprn/kmp merisation of the ortho-isomer rapid formation of the initial rates agree within the limits of experi- the para-isomer is observed although eventually a mental error with those obtained from the equi- similar equilibrium mixture is obtained as in the li brium composition.former cases. A complicating factor in the isomerisa- The apparent rate constants of isomerisation can tion is the formation of toluene-2,4-disulphonic acid from toluene-p- and -0-sulphonic acid. However its be correlated satisfactorily with desulphonation rate rate of formation is slow compared with the rates of constants and sulphonation isomer-distribution.* isomerisation under study. Sulphonation of toluene- This allows description of the isomerisation as an m-sulphonic acid does not take place.From the intermolecular process viz. desulphonation followed limiting values of [metal/ [para] and [ortho]/[para] by rapid sulphonation5 and does not need =-complex at high reaction time (1 *60 j=0.15 and 0.085 f0.015 mechanisms proposed previously.6 respectively) the equilibrium composition was cal- (Received March 27th 1963.) Spryskov Isvest. V.U.Z. M.V.O. S.S.S.R. Khim. i Khim. Tekhnol. 1961 4 981; Chem. Abs. 1962,57 16,464~; J. Gen. Chem. (U.S.S.R.),1960 30 2433. Cerfontain Duin and Vollbracht Analyt. Chem. in the press. Holleman and Caland Ber. 1911 44 2504; Muramoto Kagaku to Kogyo (Osaka) 1959 33 259; Chem. Abs., 1960 54 12,041b. Cerfontain Kort Sixma and Wanders unpublished work. Shilov and Vainshtain Ukrain. khim. Zhur. 1955 21 58; Chem.Abs. 1955,49 8845b. Dewar "The Electronic Theory of Organic Chemistry," Clarendon Press Oxford 1949 p. 230; Syrkin Yakerson and Shnol J. Gen. Chem. (U.S.S.R.) 1959 29 189. JUNE 1963 175 The Effect of Solvent Changes on the Stabilities of Initial and Transition States in Solvolysis by sN Mechanisms By W. FEATHERSTONE, E. JACKSON,and G. KOHNSTAM (SCIENCE SOUTHROAD DURHAM) LABORATORIES FORthe solvolysis of an organic halide the first-order rate coefficient (k,) is related to its value in some reference solvent (kl0) by k,lkI0 = y/yL . . . (1) where the relative activity coefficients y and y reflect the effect of solvent changes on the stabilities of the initial and transition states respectively. Previous determinations of y and yS are confined to a few volatile halides mainly t-butyl chloride and may not always be very accurate.2 We now report these parameters for the reaction of sparingly soluble chlorides with aqueous acetone.is associated with say na molecules of acetone and the transition state with na molecules of acetone and nw molecules of water. The small effect of solvent changes on the stability of the transition state for SN1 hydrolysis probably arises from opposing changes of roughly equal magnitude in the facilities for solvation by acetone and by water. The decrease of log r$in SN2hydrolysis as the solvent is made less aqueous then suggests that the transition state now requires proportionally less participation by water (i.e. a smaller value of nw/na)than for mechanism SNl in agreement with conclusions based on the heat capacities of activation5 and with earlier views.6 Relative rates and activity coeficients for soIvolysis in aqueous acetone.[Activity coefficients from k via eqn. (1) and either solubilities (which yield y) or zeroth-order rates for hydrolysis in permanently saturated solutions (which yield y:).] Mechanism SN2 Mechanism SNl A \ sf-4-NO2.CGH4CH2CI" 4-NO2.C6H,.CHPhCI* 4-NO,.C,H,.CHCl'C,H,.Ph-4t % Acetone -logk,/k,* -log y -log yt -lOgk,/k," -log y -log y$ -logk,/k," -log y -log y 45 0.161 0.258 0.096 0.343 50 0.314 0.556 0-242 0.789 55 0-436 0.744 0.317 1.149 60 0.555 0.916 0.376 __. 70 - - - - 85 _. - - - * At 0" or 1-62'; reference solvent 40% acetone.The results in the Table show that the reduction in rate caused by decreasing the water content arises from an increase in the stability of the initial state; transition-state effects make only a small contribu- tion to kl/kloin SNlsolvolysis (log k,/klo -log y) and actually oppose the observed change in rate in the S,2 reaction (log kl/klo and log y$ have the same sign). The previous work yields initial-state contributions to k,/kIo which are considerably smaller in aqueous alcohol^^^^^ than those now observed and almost negligible for changes from water to deuterium oxide.lb~* The present variations of log y and log y$ with solvent composition (see Table) are qualitatively consistent with the assumption that the initial state 0.351 0408 --0.788 -0.001 --1.078 -0.071 ---I 1.319 1.427 0.108 -2.582 2.375 -0.207 t At 20.18";reference solvent 50% acetone.In the present systems the rate of SN2hydrolysis is considerably less sensitive to solvent changes than when mechanism SNl is operating as generally observed.6 It can be seen that this arises at least partly from the greater stabilisation (or smaller destabilisation) of the transition state in SN1 hydrolysis as the ionising power of the solvent is increased. Our results do not therefore invalidate earlier interpretations6 of the different effects of solvent changes on the rates of SNland S,2 solvo-lysis. They do however show that initial-state effects can be extremely important in determining the magnitude of kl/klo irrespective of the mechanism which is operating.(Received April 26th 1963.) (a) Fainberg and Winstein J. Amer. CJzem. Sac. 1957 79 5937; (b) Clarke Taft and Williams ibid. 1962 84, 2292; Clarke and Taft ibid.,p. 2295. Olson Ruebsamen and Clifford J. Amer. Chem. Soc. 1954,76 5255. Bird Hughes and Ingold J. Chem. Sac. 1943 255. Swain and Thornton J. Amer. Chem. SOC.,1962 84 822. Kohnstam "The Transition State," Chem. SOC.Special Publ. 1962 No. 16 p. 179. Hughes Trans. Faraday Soc. 1941 37,603. I76 PROCEEDINGS Long-range Thallium-Proton Spin-Spin Coupling Constants By J. P. MANERand D. F. EVANS (IMPERIAL LONDON, COLLEGE S.W.7) PREVIOUSLY~ it was shown that in the diethylthallium cation the 205T1-H(CH3) coupling constant is larger than that for 205T1-H(CH2) and of opposite sign.This behaviour is typical of ethyl groups bonded to elements in Periods II-VI with a nuclear spin of &.2s3 To account for these anomalous constants it has been suggested that other mechanisms beside Fermi contact are important,2 or that d-electron hybridisa- tion is in~olved.~ However it has recently been shown that in saturated organic compounds the geminal and vicinal H-H coupling constants are also of opposite sign. Our present results for the 205Tl-H coupling constants suggest that they may involve essentially the same mechanism as the H-H coupling constants namely via Fermi contact involving the 6s orbital of the thallium atom. The results obtained for phenylthallium com-pounds are given in the Table.The uniform increase in these coupling constants from triphenylthallium the ortho- meta- and para-methyl groups. In mesitylene the ortho and para H-H(CH3) coupling constants are respectively 0.89 and 0-45 c./sec.,6 and the ,05Tl-H coupling constants are again about 130 times greater than the H-H coupling constants. That the 205Tl-H(para-CH3) coupling constant is larger than the corresponding meta coupling con- stant is consistent with results of calculations of the wcontribution to H-H coupling constants in aro- matic systems by Acrivos6 and by McConnell.' These results suggest that as for the corresponding H-H coupling constants the thallium coupling to the ortho and mcta ring protons is transmitted mainly via the o-electrons of the benzene ring.In contrast for the para coupling transmission via the n-electrons is imp~rtant.~ The 205T1-H(meta) coupling constant like the H-H(meta) coupling constant is anomalous-ly large in comparison for in the di-n-propylthallium cation the coupling constants areJ for 205T1-H( aCH,) TABLE.Coupling constants J in c./sec. 205T1-H(ortho) 205T1-H(rneta) 2osT1-H(para) *PhT12+ A948 IfI365 &123 *Ph,Tl+ 451 139 5i* Ph3Tlt 5259 &80 & 5 &35 i5 ,05T1-H( trans) "05Tl-H(cis) 20sT1-H(gem) "(CH =CH)Tlz+ *(CH2= CH),Tl+ 3750 1618 1806 805 2004 842 * As the perchlorate in DzO. In triniethylamine. to the monophenyithalliuni cation is a general feature for organothallium compounds regardless of the group attached to the thallium.The ratios for the 205T1-H coupling constants in R3Tl R2T1+ and RT12f are approximately 1 :1.7:4.0.4 If the ,O5T1-H coupling constants in the monophenylthallium cation are divided by about 130 the values obtained are similar in both magnitude and relative sign to the corresponding H-H coupling constants in aromatic compounds namely JH (ortho) & 6-9; JH-H(meta) Sr 1-3; JH-* & O-i c./sec.5 The 2*5T1-H(CH:3) coupling constants in the monotolyl cations are respectively 104.2 50.1,and 61.0 f0.5 c.lsec. for Maher and Evans Proc. Cliern. Soc. 1961,208. = i.341; J for 205Tl-H(,6?CH2) = 469; J for 205Tl-H(yCH3)= T 20.5 10.5 c.fsec. In the divinylthalIium and vinylthallium cations the cis and trans coupling constants have roughly the expected relative magnitudes (see Table) compared with the usual H-H coupling constants in vinyl derivatives.8 The geminal coupling constant how- ever is anomalousiy large.It is noted that the trans 205Tl-H coupling constant in the (CH = CH)T12+ cation is the largest proton coupling constant yet reported. The very large magnitudes of these 205TI-H coupling constants can be qualitatively understood Narasirnhan and Rogers J. Chem. Phys. 1961 34 1049. Stafford and Baldeschwieler J. Amer. Chem. Soc. 1961 83 4473. * Authors' unpublished data. Banwell and Sheppard Discuss. Faraday Soc. in the press. fi Acrivos Mol. Phys. 1962 5 1. 'McConnell J. Chenz. Phys. 1959 30,126. Schaeffer Canad. J. Chem. 1962,40 1.JUNE 1963 on the basis of the Fermi contact interaction as arising from the large effective nuclear charge of the thallium atom.Q Also KloselO has made valence- bond calculations based on Karplus's method,ll of coupling constants in ethyl groups bonded to heavy atoms and has obtained results of the right order of magnitude. The increase of the coupling constants in the series R,Tl R,Tl+ and RT12+ may be partly due to the increase in the s-character of the thallium- carbon bond (cf. Holmes and Kivelson12) and partly to the increased effective nuclear charge of the thal- lium. It seems likely that a similar interpretation is applicable to other proton coupling constants in- volving heavy elements of Groups II-IV such as mercury and lead.Proton resonance spectra were measured on a Varian V4311 spectrometer at 56.45 McJsec. and the relative signs of the coupling constants were determined by using double irradiati0n.l We thank the Department of Scientific and Industrial Research for financial support (to J.P.M.). (Received April 26th 1963.) Schneider and Buclcingham Discuss. Farday Soc. in the press. lo Klose Ann. Physik 1962 9 262. l1 Karplus J. Chem. Phys. 1959 30,11. l2 Holmes and Kivelson J. Amer. Gem. Soc. 1961 83 3903. The Reaction of Bicyclo[2,Z2,1]heptadienewith Methylphosphonous Dichloride By M. GREEN (DEPARTMENT OF CHEMISTRY FACULTY UNIVERSITY OF MANCHESTER) OF TECHNOLOGY RECENTLY, bicyclo [2,2,1 Iheptadiene has kn re-ported to react with boron trichloride,l phenylboron dichloride,l stannic chloride,2 phenyltin trichloride? and germanium tetrabromide to give substituted nortricyclenes.It has now been found that niethyl- phosphonous dichloride reacts with bicyclo [2,2,1]- heptadiene in the absence of light and oxygen to give a crystalline 1 :1 adduct (I). This adduct with sulphur dioxide or aqueous sodium hydrogen carbonate gave a neutral phosphine oxide (11) m.p. 157" vmax. 3-25 8-40 12.55 p that resisted hydrogenation. The proton magnetic reson- ance spectrum of this oxide measured in benzene had peaks at (T 8-07 8-13) complex T 8.43 complex (T 8-66 8.85) doublet (r 8.89 8-91 8.93) complex with area ratios 1-95 2-8 3-4 3 respectively. The doublet at (T 8.66 8.85) collapsed into a singlet (78.76) and a simplification of the complex (T 8.07 8.13) occurred on application of the spin-decoupling technique to the 31P atom.This doublet can there- fore be assigned to the group (P-CH,). Pyrolysis of the adduct (I) at 180"/0.1 mm. gave a liquid phosphonous chloride (III) vmax. 3-25 12.55 p whose proton magnetic resonance spectrum in benzene* had peaks at r 5.66 singlet (T7+79,7.97) complex r 8.31 singlet T 8-76 complex T 8-90 com- plex T 9.04 complex with area ratios 0.85 1-26 1.0 2.93 3.94 0.96 respectively. The peak at T 5.66 can be assigned to the group CHC1. This singlet could not be split under conditions of high resolution. Reaction of this chloride (111) with chlorine and then sulphur dioxide gave a liquid phosphonyl chloride (IV) vmax.3.25 8.1 12.55 p demonstrating that the former is a tervalent-phosphorus chloride. A liquid phosphiiiate ester (V) vmax. 3.25 8-25 12.55 p was formed when the product (IV) reacted with an excess of methanol suggesting that one of the chlorine atoms in (IV) is attached to a carbon atom. The presence of peaks at 3.25 and 12-55 p and the absence of absorption between 5.0 and 6-9 p in the infrared spectra of (II-V) suggest3 that these com- pounds are substituted nortricyclenes. The overlap of peaks prevents a detailed analysis of the proton magnetic resonance spectra; however the spectra are compatible with substituted nortricyclene struc- tures. It is suggested that these compounds have the structures formulated. The presence of the group * The nuclear magnetic resonance spectra of compounds (11) and (111) were also measured in CC14;no peaks corres- ponding to olefinic or aromatic protons were then observed.Joy and Lappert Proc. Chem. SOC.,1960 353. Rabel and West J. Amer. Chem. Soc. 1962 84 4169. Pollard Spectrochim. Acta 1962 18 837. CHCl as a singlet in the proton magnetic resonance spectrum of 011) and the known4 dependence of the coupling constant between vicinal hydrogen atoms on the dihedral angle suggests a structure (111) in which the chlorine atom of the CHCl group occupies an em-position. The ready reaction of methylphosphonous di- PROCEEDINGS chloride with bicyclo[2,2,1]heptadiene is probably due to the importance of a homoconjugative effect.5 A detailed mechanism of this reaction cannot be suggested on the basis of the evidence described; however it is of significance that no unsaturated isomer of compound (11) or (111) was detected.(Received April 5th 1963.) 4 Karplus J. Chem. Phys. 1959,30 ll; Anet Canad. J. Chem. 1961,39 789. Winstein and Shatavsky Chem. and Ind. 1956 59. The Mechanism of Pyrophosphate Formation from Phosphorarnidates By V. M. CLARK and S. G. WARREN CHEMICAL LENSFIELD (UNIVERSITY LABORATORY ROAD CAMBRIDGE) SINCEthe initial reports1s2 of the use of phos-phoramidates in the synthesis of pyrophosphates further development has led to a highly flexible method by which a wide variety of unsymmetrical pyrophosphates including ATP and coenzyme A has been synthesised.The mechanism of formation of the pyrophosphate link in these reactions has however awaited elucidation. We report a kinetic investigation of the formation of the diammonium salt of P,P2-dibenzyl pyrophos- phate (11) by thermal treatment of benzyl hydrogen phosphoramidate (I).! A pathway involving a meta- phosphate intermediate* would presumably be of first order with respect to phosphoramidate since the intermediate would be highly reactive and its foma- tion therefore rate-determining. On the other hand for a pathway involving external nucleophilic attack on the phosphorus atom second-order kinetics would be ~bserved.~ In dry dioxan at 70° benzyl hydrogen phos- phoramidate (I) has a half-life of 3 hr. Analysis of the infrared absorption bands corresponding to phosphoryl (P=O) stretching (1200 cm.-l in the pyrophosphate and 1270 crn.-l in the phosphora- midate) showed that the reaction followed a second- order rate law with respect to (I).An induction period (prior to pyrophosphate formation) of approximately 1 hr. was observed but this disap- peared on addition of two molar equivalents of water at the outset of the reaction. It therefore seemed likely that hydrolysis of the substrate occurred before phosphorylation. This was confirmed by chromato- graphic and spectrophotometric identification of the benzyl hydrogen phosphate anion in the reaction mixture. These observations lead us to suggest the sequence RO RO 0 RO RO OR \ / P-0-P \/0 + (1) -3 -/I1 II\-HO/ \o +O 0 00 hH4 N H4 (11) (R =CeH,*CHJ A bimolecular mechanism appears to be common to all displacements of phosphoramidates.Thus (I) has been used to extend the phosphate chains of both AMP and ADP,L without protection of the hydroxyl groups of the 2’ and 3’ positions of the ribose moiety (a highly reactive intermediary metaphosphate would not show such selectivity). Furthermore di- ethyl phosphoramidate undergoes cleavage of the P-N link when treated with gaseous hydrogen chloride to give diethyl phosphorochloridate,6 and with phenyl dihydrogen phosphate in benzene a pyrophosphate triester is obtained which reacts further with the monophenyl phosphate to yield ulti- mately sym-diphenyl dihydrogen pyrophosphate.’ Since the initial material in the last two examples is a diester of phosphoramidic acid it is clear that no metaphosphate can arise in this reaction.The results here reported differentiate the reactions of phosphoramidates from those involving carbo- Clark Kirby and Todd J. 1957 1497. Chambers and Khorana J. Amer. Chem. SOC.,1958,80,3749,3756. Moffatt and Khorana .I.Amer. Chem. Soc. 1961 83 663. Todd Proc. Nat. Acad. Sci. USA. 1959 45 1389; Butcher and Westheimer J. Amer. Clzern. SOC.,1957 77,2420; Kumamoto and Westheiiner ibid. p. 2515. Dostrovsky and Halmann J. 1953 503; Hudson and Keay J. 1956,2463 1960 1859. * Skrowaczewska and Mastalerz Roczniki Chem. 1955,29,415. Richter Ph.D. Thesis Cambridge 1961. JUNE 1963 179 di-imidess and the oxidation of quinol phosphatesQ We gratefully acknowledge the award of a Senior since acceptable evidence for the formation of meta- Scholarship by Trinity College and of a D.S.I.R.phosphate intermediates has been presented in these maintenance allowance (to S.G.W.). cases. (Received April 22nd 1963 .) Weimann and Khorana J. Amer. Chem. SOC.,1962,84,4329. Clark Hutchinson Kirby and Todd J. 1961 715. The Constitution of Munetone By S. F. DYKE (BRISTOL COLLEGE OF SCIENCE AND TECHNOLOGY) W. D. OLLIS (THEUNIVERSITY, BRISTOL) and M. F. SAINSBURY (BRISTOL COLLEGE) TECHNICAL THEisoflavone munetone was originally given the constitution (I)) which was unusual in two respects. Like tlatlancuayin,2 munetone was described as lack- ing an oxygen-containing substituent in the 4‘-position yet this is frequently present in natural isoflavones;3 and the structure (I) contained an iso- prenoid C5 residue unique in structural type among natural phenolic compounds.* Synthetical studies have now shown that this structure for munetone requires considerable revision.The Hoesch reaction5 of dihydrotubanol* with 2-methoxybenzyl cyanide gave the deoxybenzoin (11) which by reaction with ethyl orthoformate3p7 followed by dehydrogenation gave a product of expected structure (I). This material was different from natural munetone but the nuclear magnetic resonance spectrum of the synthetic isoflavone cor- responding to the deoxybenzoin (11) fully supported its structure.The nuclear magnetic resonance spec- trum of natural munetone kindly supplied by Dr. N. L. Dutta was incompatible with the structure (I) and showed that the formula of munetone should be changed from C21H180P to C25H2405. The 24 protons could then be assigned to two 2,2-dimethyl- chromen residue^,^ a methoxyl group an iso-flavonoid proton in the 2-position and two pairs of aromatic protons. One pair of aromatic protons formed an AB system (J 8.5 c./sec.) and the other pair was associated with two singlets slightly broadened by weak coupling (J 0.6 c./sec.). These characteristics and the chemical shifts1° uniquely define the structure of munetone as (111). This revised structure (111) for munetone is established by its partial synthesis from mundulone (1V).l1 Mundulone methanesulphonate and ethanolic sodium hydroxide gave a deoxybenzoin identical with muneto1,f which by reaction with ethyl ortho- f~rrnate~,~ gave munetone 011).(Received April 8th 1963.) Dutta J. Indian Chem. Soc. 1956,33 716; 1959 36 165; 1962,39 475. CrabbC. Leeming and Djerassi J. Amer. Chem. SOC.,1958 80 5258. a Venkataraman “Fortschritte der Chemie Organischer Naturstoffe,” ed. L. Zechmeister Springer-Verlag 1959, Vol. XVII p. 1 ;Ollis “The Chemistry of Flavonoid Compounds,” ed. T. A. Geissman Pergamon Oxford 1961 p. 353. * Ollis and Sutherland “Recent Developments in the Chemistry of Natural Phenolic Compounds,” ed. W. D. Ollis, Pergamon Oxford 1961 p. 74. Spoerri and Du Bois Org. Reactions 1949 5 387. Miyano and Matsui Chem.Ber. 1959 92,2491. ’ Sathe and Venkataraman Current Sci. (India) 1949 18 373. Sarin Sehgal and Seshadri J. Sci. Ind. Res. (India) 1957 16 B 61. Burrows Ollis and Jackman. Proc. Chem. SOC.,1960 177. lo Dyke Ollis and Sainsbury unpublished work. l1 Burrows Finch Ollis and Sutherland Proc. Chem. Soc. 1959 150. 180 PROCEED INGS ~ _ ~_~_ ~-~_ -The Electron Distribution in 1,s-Bisdehydro[14]annulene By N. A. BAILEY and R. MASON (CRYSTALLOGRAPHY DEPARTMENT LABORATORY OF CHEMISTRY IMPERIAL LONDON, COLLEGE S.W.7) THE identification of an unusual hydrocarbon 1,8-bisdehydro[l4 Jannulene C1,H, (I) has recently (1) been rep0rted.l Its aromaticity which is consistent with Htickel’s rules is established by the chemical shifts of the inner and the outer protons in the nuclear magnetic resonance spectrum and by the preliminary X-ray results.The molecule is particu-larly interesting in so far as it is not possible to represent the bonding in the molecule which is required to be strictly centrosyrnmetric,l by the usual KekulC formulations. A complete least-squares analysis of the room- temperature three-dimensional X-ray data has now been completed (R = 0.078); the Figures show both the electron distribution in the molecular plane and the carbon-carbon bond lengths (A) and bond angles which have average standard deviations of 0408 A and 0*4”,respectively. ,-7\ Thc molecule is planar (r.m.s. deviation 0~004.$) and has essentially mmm (&) symmetry.Apart from the triple bond the carbon-carbon bond lengths correspond to a n-bond order identical with that of benzene. The shortening of the bonds adjacent to the triple bond arises from the change of atomic radius of carbon on rehybridisation from an sp2 to an sp valency state2p3 rather than from increased n-bond- ing. n-Electron delocalisation in the molecule is com-plete and the present geometry is being used as the basis of self-consistent-field molecular-orbital calcu- lations. All the hydrogen atoms have been located by difference Fourier analysis the average carbon- hydrogen bond length being 1-08 -& 0.05 A. The separation of the inner hydrogen atoms which are essentially coplanar with the carbon framework is only 1-85 .$; this value suggests a van der Waals radius for hydrogen of approximately 0.95 A rather than the usually accepted 1.25 A? Relief of some of the repulsion between these non-bonded hydrogen atoms is reflected in the increase of the external bond angle at the carbon atoms to which they are bonded.The remaining angular deviations from strict trigonal and digonal symmetry may also be explained in terms of intramolecular electron correlation effects. The complete difference density shows features similar to those that have been reported earlie$ and together with other details of the analysis will be discussed elsewhere. We are grateful to Professor F. Sondheimer and Dr. Y. Gaoni for providing us with a sample of the compound and to Mrs.J. Dollimore Mr. 0. S. Mills and Drs. J. S. Rollett and R. Sparks for copies of their Mercury computer programmes. One of us (N.A.B.) acknowledges the receipt of a Morganite Research Student ship. (Received April 19th 1963.) Sondheimer Gaoni Jackman Bailey and Mason J. Amer. Chem. Sac. 1962 84 4595. a Coulson Victor Henri Memorial Volume Likge Desoer 1948 p. 15. Dewar and Schmeising Tetrahedron 1959 5 105. Pauling “The Nature of the Chemical Bond,” 3rd edn. Oxford University Press 1960 p. 260. Mason Proc. Roy. Soc. 1960 A 258 302. JUNE 1963 181 The Phosphorescence and Delayed Fluorescence Lifetimes of Pyrene in Liquid Paraffin B. STEWNS and M. S. WALKER OF CHEMISTRY SHEFFELD (DEPARTMENT THEUNIVERSITY 10) PARKER and HAT CHARD^ have convincingly demon- strated that the delayed component of fluorescence emitted by dissolved aromatic hydrocarbons origin- ates in the interaction of two triplet-state molecules.If any further confirmation is required it is that the rate constants kDand kT for the respective decay of delayed-fluorescence intensity and of triplet-state concentration be reliably measured for the same out- gassed solution under the same conditions; such measurements should establish the relationship k,/k = 2 * . . (1) which this mechanism requires. A 0.OlM-solution of pyrene in outgassed liquid parafi emits both delayed fluorescence and phos- phorescence over the temperature range from 0" to -30". We have measured the decay constants k and k for each emission component (isolated by appropriate optical filters) using an apparatus pre- viously constructed2 for recording luminescence decay curves with decay constants in the region of 1-lo4 sec.-l.In all cases the decay was exponential over the region of observation and standard errors in the measured decay constants obtained from least squares plots of log intensity against time amounted to less than 5 %; control experiments established that the temperature of the solution was within 0.5" of the measured temperature of the refrigerant over the temperature range covered. Values of log k are plotted against reciprocal temperature in the Figure. The upper line drawn through the log k points is a least-squares plot for the data between 0" and -30"; the lower line drawn with the same slope but displaced vertically by -log 2 [in accordance with equation (l)] is in good agreement with the experimentally observed varia- tion of log k with 7'"K-l over the same temperature range.A statistical treatment of the log k values in this range leads to the relationship kD/kT= 1.7 f 0-3,in support of Parker and Hatchard's mechanism for delayed fluorescence. At lower temperatures kT approaches the value kT0= 3.0 sec.-l recorded for the frozen solution at -196"; the corresponding lifetime of 0.33 sec. can be compared with the value of -0.2 sec. in EPA previously ob~erved.~ A similar variation in kT with temperature has been reported for 9,lO-dibromo- anthracene by Porter and Stief? the data in our Figure corresponding to the high and intermediate viscosity regions (2) and (3) recognised by these authors.However a plot of log (kT-kTo)against reciprocal temperature supplemented by log (kD/2 -k,") in the higher temperature region is quite linear over the range from 20" to -6O" which indicates that one first-order triplet-quenching pro- cess is dominant in this region. Moreover the correspondence between the observed activation energy of 11 f 2 kcal.fmole and that of -12 kcal./mole for viscous flow of this solvent5 signifies that this quenching process is viscosity-de~endent.~ 3*L 2.0- - m W Y--o" 1.0 - i30' 0' Temp. -30' **a. *.-60" 35 4.0 4.5 IOOO/T Plot of log k (open circles) and log kT (solid circles) against rec@rocal of absolute temperature for 0.Olwsolution of pyrene in liquid parafin.This research has been made possible through the support of the U.S. Department of Army through its European Research Office. (Received April 17th 1963.) Parker and Hatchard Proc. Chem. SOC. 1962 147 386; Proc. Roy. SOC.,1962 A 269 574; Trans. Faraday Soc., 1963 59 284. * Stevens and Hutton Proc. Phys. SOC.,1963 81 566. McClure J. Chern. Phys. 1949 17 905. Porter and Stief Nature 1962 195 991. Stief private communication. PROCEEDINGS ~~~ Abnormal Nucleophilic Substitution of 3-Nitrobenzylidene Chlorides By J. D. LOUDON and D. M. SMITH (CHEMISTRY THEUNIVERSITY, DEPARTMENT GLASGOW) A NOVEL and interesting variant of nucleophilic substitution at an aromatic centre is provided by the action of sodium methoxide on the benzylidene chloride (I).Entry of methoxide ion into the aro- matic nucleus with expulsion of a chloride ion from the side-chain leads to the methoxybenzyl chloride (11) of which the structure has been proved by in- dependent synthesis. Similar attack by ethoxide ion yields the corresponding ethoxybenzyl chloride in 70% yield. On the other hand by the action of piperidine on the compound (I) both chlorine atoms are replaced and the normal benzylidenedipiperidine (W (a> (I; NC,H, for each C1) is formed together with the R= SO;C6H4*M.-p abnormal product (111). sulphonyl group in compound (I) may be expected These reactions extend and elucidate some to assist the abnormal reaction (a) by contributing observations by Kliegl and Holle which have been to electrophilicity in the nucleus and (b)by hindering overlooked in current surveys.Kliegl and Holle the approach of an external reagent to the chlorine- found that 3-nitrobenzylidene chloride in reactions bearing carbon atom. The practical result by with sodium methoxide ethoxide and n-propoxide defining the initial stage as in (I) -(11) disposes of gave small but in that order increasing proportions the possibility that the abnormal reaction proceeds of 2,5-and 4,3-alkoxynitrobenzyl alkyl ethers at the through an acetal-type of intermediate and a derived expense of the normal acetals. The toluene-p-entity such as (IV). (Received April 5th 1963).Kliegl and Holle Ber. 1926 59 901. Naturally Occurring Aliphatic Nitro-compounds ;The Endecaphyllins By R. A. FINNEGAN and M. P. MORRIS* W. H. MUELLER (DEPARTMENT OF CHEMISTRY OHIO STATE UNIVERSITY COLUMBUS 10 OHIO U.S.A.) ALTHOUGH the toxicity of Indigofera endecaphyiia whole plant.* Silica-gel chromatography has now Jacq. has been recognised for several years,l chemical provided in addition to this acid a number of examination2-* has led to the isolation of but a single crystalline compounds including six aliphatic nitro- pure substance p-nitropropionic acid,2 previously compounds. These compounds called endecaphyllin obtained by hydrolysis of hiptagin5 and karakh6v7 A-E are listed in the Table along with a seventh These along with l-nitro-2-phenylethane,8appear nitro-compound (X) which was isolated directly to be the only previously reported naturally occurring from the crude extract.aliphatic nitro-compo~nds.~ The presence of CH,*NO groups in these Our work with an acetone extract of the leaves and substances was indicated by infrared bands near stems of I. endecaphyila was prompted by observa- 1550 cm.-l by ultraviolet maxima near 270 m,u and tions that the toxic properties of fhitropropionic by chemical tests.ll The sizes of the extinction acid2*3J0 apparently do not correspond to those of the coefficients for the ultraviolet bands support the * Food and Drug Administration Washington D.C. Warmke Freyre and Morris Agron. J. 1952,44,517; Nordfeldt Henke Morita Matsumoto Takahashi Younge Willers and Cross Univ.Hawaii Agric. Exp. Station Tech. Bull. No. 15 July 1952; Emmel and Ritchey J. Amer. Soc. Agron. 1941,33 675. Morris Pagan and Warmke Science 1954 119 322. Cooke Arch. Biochem. Biophys. 1955 55 114. * Hutton Windrum and Kratzing J. Nutrit. 1958 64 321; 1958 65 429; Coleman Windrum and Hutton ibid. 1960 70 267. Gorter Bull. Jard. But. Buitenzorg. 1920 2 187. 6 Carter and McChesney Nature 1949 164 575; Carrie J. SOC.Chem. Ind. 1934 53 288~;Carter ibid 1943. 62 238~. Carter J. Sci. Food Agric. 1951 2 54. * Gottlieb and Magalhaes J. Org. Cliern.,1959 24 2070. Cf. Pailer “Fortschritte der Chemie organischer Naturstoffe,” 1960 Vol. XVIII p. 55. lo Rosenberg and Zoebisch Agron. J. 1952 44 315. JUNE 1963 183 Endecaphyllin M.p.Formula B and C as isomeric tri-O-(P-nitropropionyl)-D-A 120- 122" C15H2,N3015 glucopyranose derivatives (I; n = 3) D and C as B 125-1 26.5 C15H21N3015 analogous diesters (I; n = 2) and X as a tetraester Bl 129-130 C1,H23N30,5 (I; n = 4). Compound B is probably a triester of c 150-152-5 C15HS1N3015 methyl p-D-glucopyranoside (this glycoside also D 145-146 C12H,,Nz012 occurs free in the plant). E 132-134 C12H18N2012 X 104-105*5 Cl8HS4N,O1 (I) C,H,,-,O,(CO*CH,*CH,.NO,) conclusion that all the nitrogen atoms are present in The melting point and rotation of endecaphyllin A nitro-groups. The materials are non-basic and amide are nearly identical with those reported for karakin,7 absorption bands are absent from the infrared 1,4,6-tri-O-(P-nitropropionyl)-D-glucopyranoside, spectra which show in addition to the nitro-bands and it is possible that the two substances are identical.hydroxyl and saturated-ester absorption. Further However conditions reported' to provide karakin hydrogenation results accorded with those expected diacetate (m.p. 103") afforded only a monoacetate of for complete reduction of all nitro- to amino-groups. endecaphyllia A (m.p. 125-5-126-5"). The detailed Paper chromatography of endecaphyllin hydro- structures of the endecaphyllins are expected to lysates resulted in the detection of p-D-glucose and result from degradative and synthetic work now in S-nitropropionic acid along with several unidentified progress. compounds which probably result from partial hydrolysis. This investigation was supported by The Division The combined analytical spectral and chemical of General Medical Sciences U.S.Public Health properties allow the formulation of endecaphyllin A Service. (Received March 8th 1963.) l1 Noller "Chemistry of Organic Compounds," W. B. Saunders Co. Philadelphia Pa. 1951 p. 255; Dannley and Kitko Analyt. Chem. 1960 32 1682; Meyer and Locher Ber. 1874 7 1510. The Synthesis of the Antibiotic P.A. 147 [5-Hydroxy-3-vinyin-2(5H)-one] By D. K. BLACKand S. R. LANDOR (WOOLWICH LONDON, POLYTECHNIC S.E.18) THE powerful antibiotic P.A. 147 previously isolated W2=C,' H from a Strepromyces strain1*2 and identified as I EtMq& 5-hydro~y-3-vinylfuran-2(5H)-onel~~ (V) has been CH,=CH-O-CH,-C=CH 5Yq-/0 synthesised through an allenic intermediate.The (1) H02C-C ZC-CH Grignard reagent from propargyl vinyl ether* (I) and ethylmagnesium bromide gave the acid (11) on treat- ment with carbon dioxide. This acid was passed in a stream of nitrogen? through an electrically heated ($4-CHO ?H,-CHO tube containing glass wool and the products were -HO,C-C=C=CH, HC\ condensed in a cooled trap and chromatographed on H2C=U-i C02H deactivated alumina. This led to the lactol (V) a yellow oil Vmax. 3400 1780 1750 1640 Am,,. (IV) % 245 mp (E 8800). After titration with O-lN-sodium HC-CH-OH hydroxide it had Amax. 273 mp (E 19,320) which is ll >o typical for the conjugated dienal system present in CH,=CH-C-(v) CO the anion of the open-chain acid (IV). Hydrogenation (two equivalents of hydrogen absorbed) gave the aldehyde (111) which rapidly changes prototropicalfy saturated lactol whose semicarbazone m.p.158" to the 2,4-dienal and the lactol (V) with which it is in (1; t,l 158-1 59") had the correct analysis. equilibrium. It is suggested that a Claisen-Cope type rearrange- We thank the D.S.I.R. for a maintenance grant to ment of the acid (11) gives the unisolated allenic D.K.B. (Received May 3rd 1963.) * Els Sobin and Celmer J. Amer. Chem. Soc. 1958 80 878. * Prepared by interaction of dipropargyl acetal and boron trichloride followed by treatment with trimethylamine Akita Okami Suzuki Maeda Takeuchi and Umezawa J. Antibiotics A 1962 130. and pyrolysis of the complex; this unpublished general method for the preparation of ally1 and propargyl vinyl ethers was developed in our laboratory.We had previously shown (Black Landor and in part Demetriou unpublished work) that propargyl vinyl ethers could be converted into allenic aldehydes; cf. parallel work on propargyl acetals by Jones Loder and Whiting (Proc. Chern. Soc. 1960 180). PROCEEDINGS NEWS AND ANNOUNCEMENTS Library.-On Thursday July 4th the Library will close at 5 p.m. It will also close at 6 p.m. on Friday August 2nd and will re-open at 9.30 a.m. on Wednesday August 7th 1963. The Corday-Morgan Medal and Prize.-This Award consisting of a Silver Medal and a monetary Prize of 400 guineas is made annually to the Chemist of either sex and of British Nationality who in the judgement of the Council of the Chemical Society has published during the year in question and in the immediately preceding five years the most meritor- ious contribution to experimental chemistry and who has not at the date of publication attained the age of thirty-six years.If in the opinion of the Council two or more candidates are of equal merit a medal may be awarded to each and the prize divided equally among them. Copies of the rules governing the Award may be obtained from the General Secretary of the Society. Applications or recommendations in respect of the Award for the year 1962 must be received not later than December 31st 1963 and applications for the Award for 1963 are due before the end of 1964. Election of New Fellows.-69 Candidates were elected to the Fellowship in May 1963.Deaths.-We regret to announce the deaths of the following Mr. G. Adarns (30.3.63) Stourbridge a Fellow since 1914; Dr. R. F. Hunter (2.5.63) Research Co-ordinator at Bakelite Limited Birming- ham; Dr. D. C. Quin (21.4.63) Research Chemist at the Distillers Company Limited Epsom; and Lt.-Col. F. M. Potter (3.5.63) Director Scottish Tar Distillers Falkirk. Medway College of Technology.-A two-day Symposium on “Recent Work in Biosynthesis,” will be held with the support of the Society at the Medway College of Technology on September 19-20th 1963. Speakers will include Professor D. H. R. Barton Professor A. R. Battersby and Dr. J. W. Cornforth and further details and application forms may be obtained from the Organisers Department of Science Medway College of Technology Horsted Maidstone Road Chatham Kent.Visit to University College of Rhodesia and Nyasa1and.-Professor F. Sebba Professor of Physical Chemistry at the University of the Wit- watersrand recently visited the Department of Chemistry under the auspices of the Chemical Society. He gave three lectures to mixed audiences of students staff and local scientists entitled “Physical Chemistry of Mineral Flotation,” “Ion Flotation,” and “Recent Advances in Catalysis.” He also visited the Government Metallurgical Labora- tory and the Mazoe Consolidated Gold Mine. Imperial College of Science and Technology.- Courtaulds Limited have agreed to provide the sum of S20,000 to help Professor A.R. Ubbelohde Head of the Department of Chemical Engineering and Chemical Technology with the many needs in con- nection with a major new extension for the Depart- ment which is being erected as part of the College’s Jubilee Expansion Scheme. Van’t Hoff Fund.-The Committee of the Van’t Hoff Fund for the endowment of investigations in the field of pure and applied chemistry invites applications for grants from the fund. The amount available for next year is about 2,000 Dutch guilders. Applications should be sent by registered post to Het Bestuur der Koninklijke Nederlandse Akademie van Wetenschappen bestemd voor de Commissie van het “Van’t Hoff Fonds,” Trippenhuis Kloveniersburgwal 29 Am-sterdam before December lst 1963. The purpose for which the grant is required the reasons for the application and the amount desired must be stated.Grants from the Fund for 1963 were awarded to Dr. G. Billek (Vienna) Dr. J. Schell (Ghent) and Dr. S. G. Tandon (Jabalpur India). R.I.C. Film Index.-The third edition of the “Index of Chemistry Films” is now available. It con- tains up-to-date details of about 1,200 films and 300 filmstrips on chemistry and related topics classified by subject followed by the addresses of the dis- tributors and an alphabetical list of titles. The date of production of each film is also given. Copies may be obtained from the Royal Institute of Chemistry 30 Russell Square London W.C.1 price 7/6. International Symposia etc.-The Sixth Inter- national Congress of Nutrition under the auspices of the International Union of Nutritional Sciences will be held in Edinburgh on August 9-15th 1963.Further enquiries should be addressed to Miss A. D. Watson Honorary Organising Secretary Clinical Chemistry Department Royal Infirmary Edinburgh 3. The Fifth International Symposium on Gas Chromatography organised by the Institute of Petroleum Gas Chromatography Discussion Group will be held at Brighton on September 8-10th 1964. Intending delegates or those wishing to submit papers should write to the Organising Office,Fifth International Symposium on Gas Chromatography 61 New Cavendish Street London W.l. Personal.-The Hon. R. J. Asheton has been appointed to the board of Borax (Holdings) Ltd. Dr.R. W.Bailey has been elected Chairman of the Manawatu Branch of the New Zealand Institute of Chemistry. JUNE 1963 Dr. V. C. Barry has been elected Treasurer of the Royal Irish Academy. Mr. S. G. Brooker has been elected Vice-president of the New Zealand Institute of Chemistry. Dr. E. Bullock formerly of Nottingham Univer- sity has been appointed Head of the Department of Chemistry of the Memorial University of New- foundland Canada. Dr. J. I. G. Cadogan has been appointed to the Purdie Chair of Chemistry in St. Salvator’s College St. Andrews from October lst 1963. Mu. W. E. Cash has been appointed Technical Adviser to the Chairman of the Chemical and Plastics Group Distillers Company Limited. Mr. H. A. Collinson has been re-elected Vice- Chairman of the British Plastics Federation.Mr. P. Day has been elected to a Junior Research Fellowship in Chemistry at St. John’s College Oxford as from October lst 1963. Mr. J. A. Dean has been appointed Manager of the Research and Development Department of A. Boake Roberts & Company Limited. Dr. A. J. Downs has been promoted from Senior Demonstrator to Lecturer in Inorganic Chemistry at King’s College Newcastle-upon-Tyne. Dr. A. Fischer of the University of Canterbury N.Z. has been promoted to a Senior Lectureship. The Honorary Degree of D.Sc. has been conferred on Sir Howard W. Flovey Honorary Fellow by the University of Hull. The University of Sussex have announced that the following have been appointed Lecturers in Chem- istry Dr.M. H. Ford-Smith Dr. R. D. Guthrie Dr. J. G. Stamper. Dr. W.P. Grove Director Radiochemical Centre Amersham was present as observer at the National Conference on Atomic Energy Isotopes and Radia- tion Pretoria in April and afterwards lectured at the University of Natal Pietermaritzburg. Mr. P. D. Gujral is now Assistant Editor in the Publications and Information Directorate C.S.I.R. New Delhi working for the Indian Journal of Chemistry and the Journal of Scientific and In- dustrial Research. Dr. D. Hall who has returned to the University of Auckland N.Z. after a study period at the Univer- sity of Pittsburgh has been promoted to Associate Profess or. The title of Professor of Nuclear Technology has been conferred on Mr.G. R. Hall in respect of his post at the Imperial College of Science and Tech- nology London. Mr. K. H. Handy Works Manager of Monsanto Chemicals Limited Ruabon is to become General Manager of Production at the London Head-quarters. Professor S. H. Harper after having served for seven years as Dean of the Faculty of Science of University College of Rhodesia and Nyasaland has been appointed Vice-principal whilst retaining the Headship of the Department of Chemistry. Recent Staff appointments include Dr. J. G. Sheppurd as Lecturer in Physical Chemistry and Mr. R. M. Letcher as Assistant Lecturer in Organic Chemistry. The Royal Society and the Leverhulme Trust announce that Professor R. D. Haworth who retires this year as Firth Professor of Chemistry and Head of the Chemistry Department University of Sheffield will visit Madras University as Visiting Professor in the field of Organic Chemistry.Mr. D. Layton has been appointed Deputy Head of the Department of Education at Leeds University from July lst 1963. Dr. R. Lessing and Mr. R. C. Odams have been elected to the Council of the British Chemical Plant Manufacturers with Mr. Odams as Vice-chairman. Professor D. R. Llewellyn has been appointed Assistant Vice-Chancellor of the University of Auckland N.Z. with special responsibility for buildings. Mr. W.R. Longworth has been appointed Planning Controller at Fisons Fertilizers Limited. Dr. A. Maccoll Reader in Chemistry at University College has been appointed to a Chair of Chemistry tenable at that College.Mi-. P. J. March has been appointed General Manager of the Plastics and Rubbers Division of Shell Chemical Company Limited. Professor C. A. McDowell of The University of British Columbia will be spending the 1963-64 academic year in the Department of Theoretical Chemistry University of Cambridge. Mr. W. D. Morton has become General Manager of G.E.C. Witton Engineering Works. Dr. L. N. Muluy formerly of the University of Cincinnati has been appointed an Associate Pro- fessor at the Pennsylvania State University Univer- sity Park Pennsylvania. Dr. K. R. Payne has been appointed General Manager of L. Light and Company Limited in succession to Mr. G. R. Jones. Professor G.Porter at present Professor of Physical Chemistry is to be the Firth Professor of Chemistry and Head of the Department of Chem- istry of Sheffield University as from October lst 1963. He has also been elected Professor of Chem- istry at the Royal Institution an honorary appoint- ment which is a revival of a Professorship which has not been occupied since 1868. Mr. P. Powell has been elected to a Junior Research Fellowship at Merton College Oxford. Dr. R. E. Richards Fellow of Lincoln College Oxford Reader in Physical Chemistry has been f 86 PROCEEDINGS appointed to Dr. Lee’s Professorship in Chemistry with effect from October lst 1964 in succession to Sir Cyril Hinshelwood. Dr. P. S. Sarin of Brandeis University has been appointed a Research Fellow in Medicine at the Harvard Medical School.Dr. J. Shorter has been appointed a Senior Lecturer in the University of Hull. Dr. B. P. Strardghan a FelIow of King’s College Newcastle-upon-Tyne has been appointed as Research Assistant in Inorganic Chemistry. Dr. J. M. Tedder has been appointed Reader in Organic Chemistry at the University of Sheffield. Honorary degrees of Doctor of Science were con- ferred on Lord Todd Sir Harry Melville and Dr. V. PreIog at Liverpool University on May 4th 1963. Mr. J. Vaughan of the University of Canterbury N.Z. has been appointed to the newly-created second Chair of Chemistry in that University. Sir Owen Wansborough-Jones has retired as a member of the National Research Development Corporation on the expiry of his period of appoint- ment.Professor F. L. Warren of the University of Natal has been appointed a member of the Scientific Advisory Council recently created by the Govern- ment of South Africa. Dr. R. G. Wilkins of the University of Sheffield has accepted a post at the State University of New York. Mr. J. Wright has been promoted to a Lectureship at the University of Canterbury N.Z. OBITUARY NOTICE WILLIAM CHARLTON 1902-1962 WILLIAMCHARLTON was born in December 1902 in Newcastle-on-Tyne and was educated there at Rutherford College Boys’ School and Armstrong College of the University of Durham where in 1925 he gained First Class Honours in the B.Sc. examina- tion. At this time his professor W.N. (later Sir Norman) Haworth moved to Birmingham and Charlton went with him as one of his first research students. There he played a small but useful part in the work of that now famous school in laying the foundations of our knowledge of sugar chemistry. He was a collaborator in the important paper (Charlton Haworth and Peat J. 1926 p. 89) in which conclusive evidence is adduced for the pyranose structure of glucose and related sugars. It was followed by papers on “The Constitution of the Disaccharide Melibiose and its relation to Raffinose” (Charlton Haworth and Hickinbottom J . 1927 1527) “The Structure of 2,3,4-trimethylglucoside” (Charlton Haworth and Herbert J. 1931 2855) and “The Constitution of a-and /%fructose di- acetones” (Anderson Charlton Haworth and Nicholson J.1925 1337). He was awarded the degree of Ph.D. at Birming- ham in 1928 as a result of this work and then joined imperial Chemical Industries Ltd. For the first two years he was seconded to work with J. Kenner at Manchester. This was at a time when Imperial Chem- ical Industries Ltd. was laying the foundations of the close association with British Universities it has held since and that set the pattern which has since been copied by most of the major chemical firms in this country and the U.S.A. He worked with Kenner at the (then) Manchester College of Technology until the end of 1930 and published papers on nitration of oximes (Charlton Earl Kenner and Luciano J. 1932 30) and on the synthesis of polyhydric alcohols related to carbohydrates (Charlton and Kenner J.1932 750). At the end of this period he was posted to the Research Department of the then Imperial Chemical Industries Ltd. Dyestuffs Group at Blackley and worked there for the rest of his life. His early re- searches were on dyestuff intermediates and dyes of the thioindigoid class the manufacture of which was at that time being developed at Blackley. In 1937 he was transferred to the Synthetic Resins Section of the department the main interest of which at that time was in the so-called alkyd resins the polycondensa- tion products of glycerol and similar polyhydric alcohols with phthalic anhydride and the anhydrides of other polycarboxylic acids which have become of JUNE 1963 great industrial importance as media for paints and in coating compositions generally.From this date on this was to prove his life's work. He rose in due course to become Head of his Section and the success of Imperial Chemical Industries Ltd. in this field of endeavour owes much to his leadership and his own personal work. Charlton was a quiet retiring and reserved man. In his work he did not spare himself and he set him- self the highest standards of achievement. He gave the most careful thought to any problem before making up his mind but when he had once reached a decision he adhered to it. Among the large technical staff at Blackley he had few intimates but he was always most friendly and helpful and was held in the highest esteem by all his colleagues.His outside interests matched his character and personality. He Nobel Prize winners in chemistry 1901-1961. E. Farber. Pp. 341. Abelard-Schuman. London. 1963. (Presented by the publisher.) Dictionnaire de chimie. L. M. Granderye. Pp. 655. Dunod. Paris. 1962. (Presented by the publisher.) Dictionnaire chimique anglais-franpis mots et Locutions frhuemment rencontrh dans les textes anglais et americains. R. Cornubert. (Contribution au dkveloppement de la Recherche Chimique-2). 3rd edn. Pp. 216. Dunod. Paris. 1963. (Presented by the publisher.) Kirk-Othmer encyclopaedia of chemical technology. R. E. Kirk and D. F. Othmer. Edited by A. Standen. Vol. 1 A-aluminium. 2nd edn. Pp. 990. Interscience Publ.Inc. New York. 1963. Advances in chemical physics. Edited by I. Prigogine. Vol. 5. Pp.410. Interscience Publ. Inc. New York. 1963. Struktur und physikalische Eigenschaften der Mole-iile. M. W. Wolkenstein. Pp. 770. B. G. Teubner Verlagsgesellschaft. Leipzig. 1960. The Radiochemical Manual. Part 2 Radioactive Chemicals:an introduction for users of radioisotopes and labelled compounds; by staff of the Radiochemical Centre Amersham Pp. 78. Radiochemical Centre. Amersham. 1963. (Presented by Dr. C. C. Evans.) Progress in inorganic chemistry. Edited by F. A. Cotton. Vol. 4. Pp. 577. Interscience Publ. Inc. New York. 1962. Inorganic Syntheses. Edited by J. Kleinberg. Vol. 7. Pp. 335. McGraw-Hill. New York. 1963. Gmelins Handbuch der anorganischen Chemie.System-nummer 524hrom-Teil A. Lieferung 2. 8th edn. Pp. 730. Verlag-Chemie. Weinheim. 1963. Solubility constants of metal oxides metal hydroxides and metal hydroxide salts in aqueous solution. W. was a keen and very knowledgeable bibliophile with a particular interest in mediaeval French literature. At times he entertained his selected associates with free translations from this source. He was keenly interested in music and also in its electrical reproduc- tion and he played both the piano and the organ with skill and feeling. His last years were clouded by ill-health. He had to spend periodical spells in hospital for physical examinations unpleasant visits to which he faced u'p with outstanding fortitude and good humour.In fact only his closer associates knew of them. He was very upset by the death of his wife some two years ago and himself died of a heart attack in hospital last December. He leaves a son Alan a botanist at present studying for a higher degree at Manchester University. H. A. PIGGOTT. Feitknecht and P. Schindler. (Pure and Applied Chem- istry. Vol. 6 no. 2.) Pp. 130-199. Butteworths Scientific Publ. London. 1963. Advances in organic chemistry. Edited by R. A. Raphael E. C. Taylor and H. Wynberg. Vol. 3. Pp.333. Interscience Publ. Inc. New York. 1962. Methoden der organischen Chemie. J. Houben and Th. Weyl. Edited by E. Miiller. Vol. 12 i. 4th edn. Pp. 683. Thieme. Stuttgart. 1963. Polyurethanes chemistry and technology. Part 1.Chemistry. J. H. Saunders and K. Frisch. (High Polymers -Vol. 16 Part 1.) Pp. 368. Interscience Publ. Inc. New York. 1962. Die atherischen Ole. E. Gildemeister and Fr. Hoffmann. Vol. IIIc. 4th edn. Pp. 510. Akademie-Verlag. Berlin. 1963. Einfiihrung der Athinyl-und Alkinyl-Gruppe in organische Verbindungen. W. Ziegenbein. (Mono-graphien zu Angewandte Chemie und Chemie-Ingenieur Technik-No. 79.) Pp. 187. Verlag-Chemie. Weinheim. 1963. Sugli acidi pirrolici. R. A. Nicolaus and R. Scarpati. (Memoria estratta dal Vol. IV Series 3a N. 3 degli Atti dell' Accademia delle Scienze fisiche e matematiche dl Napoli.) Pp.115. Accademia Sci. Fis. Mat. Naples. 1962. (Presented.) Advances in carbohydrate chemistry. Edited by Me1ville.L. Wolfrom and R.S. Tipson. Vol. 17. Pp. 504. Academic Press. New York. 1962. Methods in carbohydrate chemistry. Edited by R. L. Whistler and M. L. Wolfrom. Vol. 2. Pp. 572. Academic Press. New York. 1963. Advances in protein chemistry. Edited by C. B. Anfinsen et al. Vol. 17. Pp. 412. Academic Press. New York. 1962. Proteins and nucleic acids structure and function. M. F. Perutz. (8th Weizmann Memorial Lecture Series April 1961.) Pp. 211. Elsevier. Amsterdam. 1962. Oxygenases. Edited by 0.Hayaishi. Pp. 588. Academic Press. New York. 1962. Methods in enzymology. Edited by S. P. Colowick and N. 0. Kaplan. Vol. 5. Pp. 1087. Academic Press. New York. 1962. Vitamins and hormones advances in research and applications. Edited by R. S.Harris and I. G. Wool. Pp. 707. Academic Press. New York. 1962. Vitamin BIZ and Intrinsic Factor. Edited by H. C. Heinrich. 2. Europaisches Syposion uber Vitamin BIZ und Intrinsic Factor held in Hamburg 1961. Pp. 798. Enke. Stuttgart. 1962. Methods of biochemical analysis. Edited by D. Glick. Vol 11. Pp. 442. Interscience Publ. Inc. New York. 1963. Handbuch der analytischen Chemie. Edited by W. Fresenius and G. Jander. Part 2 Vol. 4a 1 :Kohlenstoff, Silicium. Pp. 220. Springer-Verlag. Berlin. 1962. IP standards for petroleum and its products. Part 1 Methods for analysis and testing. 22nd edn. Pp. 80. Institute of Petroleum. London. 1963. Selected values of properties of chemical compounds. Issued by the Manufacturing Chemists Association Research project.Manufacturing Chemists Assoc. Texas. 1955 onwards. (Presented by the publisher). Solvents from I.C.I. Heavy Organic Chemicals Divi- sion. Pp. 80. Imperial Chemical Industries Ltd. Billing- ham. 1963. (Presented by I.C.I.) Cereal laboratory methods. Compiled by the Com- mittee on Revision American Association of Cereal Chemists Inc. M. M. MacMasters. 7th edn. American Association of Cereal Chemists. St. Paul Minnesota. 1962. Waterproofing and water-repellency. Edited by J. L. Moilliet. Pp. 502. Elsevier. Amsterdam. 1963. Proceedings of the Fifth Conference on Carbon held at the Pennsylvania State University Pennsylvania 1961. Sponsored by the American Carbon Committee and the Pennsylvania State University. Vol. 2. Pp.673. Pergamon Press. New York. 1963. Reactions of co-ordinated ligands and homogeneous catalysis a symposium sponsored by the Division of Inorganic Chemistry at the 141st Meeting of the American Chemical Society Washington 1962. Daryl H. Buscli-Chairman. (Advances in Chemistry Series no. 37.) Pp. 255. American Chemical Society. Washington. 1963. Proceedings of the Fifth Conference on Analytical Chemistry in Nuclear Reactor Technology Gatlinburg Tennessee 1961. Sponsored by Oak Ridge National Laboratory. Pp. 356. U.S. Atomic Energy Commission. Oak Ridge. 1962.
ISSN:0369-8718
DOI:10.1039/PS9630000157
出版商:RSC
年代:1963
数据来源: RSC
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