摘要:

Several 1-methyloxindohdyl-3-methines have been synthesized, either by condensation of 1-methyloxindole with an aldehyde, or by a Wittig reaction of a chloromethylene compound with a 1-methylisatin When examined m the mass spectrometer the expected ion reactions were observed and, in addition, a reaction involving expulsion of the carbonyl group of the oxindole moiety and rearrangement of the residual fragment, to give a 1-methylbenzo[b]azepinium ion was observed. The anions of the oxindolidyluracilmethines4and5, (R = Me, R′ = OH) had an absorption band near 380 mμ but the corresponding neutral molecules absorbed at 325–350 mμ. The 5-nitrofuran derivatives3were the only compounds that inhibited the growth ofBacillussubtilis.

ISSN:0008-4042    

DOI:10.1139/v68-357

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

An additivity scheme which takes into account the interactions between ortho substituents is applied to 39 proton shifts in 22 tri-, tetra-, and pentasubstituted halobenzenes as 3 mole % solutions in cyclohexane and carbon tetrachloride. The shift of any proton can be written as the sum of two parametersD(X,Y) and one parameterdp.D(X,Y) refers to a pair of substituents placed ortho (X) and meta (Y) to the proton anddprefers to a substituent placed para to the proton. The mean deviation between observed and calculated shifts is found to be 0.010 p.p.m. for the cyclohexane solutions and 0.012 p.p.m. for the carbon tetrachloride solutions. The scheme also works reasonably well for mono and dihalobenzenes. The parameterD(X,Y)–D(H,Y) is a measure of the steric interaction between the X and Y substituents. It is also suggested that the steric environment of a proton is important in determining the shift in carbon tetrachloride solution.

ISSN:0008-4042    

DOI:10.1139/v68-358

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

In the course of the synthesis of 3β-hydroxy-21,21-dimethoxy-5β-pregnan-20-one (8), a method was developed for the preferential reduction of steroid 3-ketones of the A/B-cisseries to the axial 3β-alcohols, the stereochemistry in positions-3 and -5 of which corresponds to that of the truly active steroid cardiotonics. This method, which seems the best available to date, consists of a Meerwein–Ponndorf reduction carried out over a very short reaction period.

ISSN:0008-4042    

DOI:10.1139/v68-359

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

4-Alkylidene-5(4)-oxazolones (1) react with sodium azide in acetic acid in 5 min, or with hydrazoic acid m benzene to give the diazide2. The latter gives by thermolysis the oxadiazine (4), which forms on hydrolysis the diamide (5). The corresponding monoazides (3) react with sodium azide – acetic acid mixture to give the corresponding diazides.4-Arylidene-5(4)-oxazolones (8) react under the same conditions to give α-[tetrazolyl-(1)]-acryhc acid derivatives (9).The work of Deorha and Gupta (6) is reinvestigated. The constitution of the products is discussed chemically and spectroscopically.

ISSN:0008-4042    

DOI:10.1139/v68-360

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Seven alkyl substituted methyl cyclopropanecarboxylates with an alkyl groupcisto the ester group have been found to ring open to the isomeric γ,δ-unsaturated ester through a 1,5-hydrogen shift upon heating to 259.4 °C in a sealed tube. Methyl cyclopropanecarboxylates which do not have acis2-alkyl group are unaffected when heated for longer periods at this or higher temperatures and thus a simple method for determining geometrical isomers in this series is now available. The reactions are first-order, with ΔH† between 25 and 38 kcal/mole and ΔS† between −8 and −37 e.u. This and other information fully supports a cyclic hydrogen transfer mechanism.

ISSN:0008-4042    

DOI:10.1139/v68-361

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Methylcis-4-methyl-2-pentenoate (1) has been found to rearrange at 252 °C by a simple first-order and presumably unimolecular mechanism to methyl 4-methyl-3-pentenoate (3) with a rate constantkof 4.28 × 10−5 s−1. The heat of activation ΔH†, was determined to be 37.5 ± 2 kcal/mole and the entropy of activation, ΔS†, was determined to be −8.2 ± 4 e.u. These activation parameters and the steric requirements of the reaction support a mechanism involving a cyclic 1,5-transfer of hydrogen. Studies on the isomerization of methylcis-2-pentenoate, methylcis-2,4-dimethyl-2-pentenoate, and methylcis-2-methyl-2-pentenoate to the corresponding 3-pentenoates suggest that the 1,5-hydrogen transfer mechanism could well be general for the equilibration of α,β- and β,γ-unsaturated esters.An isopropyl groupcisto a methyl or a carbomethoxy group on a double bond is shown by nuclear magnetic resonance to prefer a conformation with the methyls of the isopropyl group held away from the methyl or carbomethoxy group. Acishydrogen does not restrict the conformation of the isopropyl group.

ISSN:0008-4042    

DOI:10.1139/v68-362

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

From the Friedel–Crafts reaction of chloral and naphthalene, others have reported the isolation of only 2-naphthyl(trichloromethyl)carbinol. Our reexamination of this reaction has shown that a mixture of 1- and 2-naphthyl(trichloromethyl)carbinols is obtained and that 80 to 90% of the product consists of the 1-naphthyl(trichloromethyl)carbinol. The 1- and 2-naphthyl(trichloromethyl)carbinols, their acetates, and their methyl ethers differ in their nuclear magnetic resonance (n.m.r.) spectra in that the signal of the α-hydrogen of the side chain of the 1-naphthyl isomer always occurs 0.8 p.p.m. downfield compared to the signal of the α-hydrogen of the corresponding 2-naphthyl isomer. This is because the α-hydrogens in the 1-naphthyl series of these compounds are in the region between the 1- and 8-positions of the naphthalene ring and subject to the ring currents of both benzenoid rings.The mixture of crude naphthyl(trichloromethyl)carbinols was converted to the mixture of α-methoxynaphthylacetic acids, and these were separated. A small amount of α,α′-dimethoxy-1,5-naphthalenediacetic acid was also obtained, demonstrating that a certain amount of 1,5-substitution occurred in the Friedel–Crafts reaction of naphthalene and chloral.

ISSN:0008-4042    

DOI:10.1139/v68-363

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

5,6-Anhydro-1,2-O-isopropylidene-α-D-glucofuranose reacts with sodium cobalt tetracarbonyl and carbon monoxide in methanol to afford methyl 6-deoxy-1,2-O-isopropyhdene-α-D-gluco-heptofuranouronate (3) in 82% yield. Treatment of tri-O-acetyl-1,2-anhydro-D-glucopyranose with sodium cobalt tetracarbonyl in ether gives 3,4,6-tri-O-acetyl-D-glucal. The 2,3-anhydro sugars are resistant to cleavage by cobalt tetracarbonyl anion in ether or in methanol. Sugar acetates are de-O-acetylated by treatment with sodium cobalt tetracarbonyl in ether–methanol.

ISSN:0008-4042    

DOI:10.1139/v68-364

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Methyl tri-O-acetyl 2-deoxy-2-iodo-β-D-glucopyranoside reacted at room temperature with sodium cobalt tetracarbonyl and carbon monoxide in ether to give in high yield methyl 4,6-di-O-acetyl-2,3-dideoxy-β-D-erythro-hex-2-enoside (5). Under the same reaction conditions the corresponding 2-iodo-α-D-mannopyranoside failed to react, but at 100 ° it was smoothly converted into the anomeric α-D-erythro-hex-2-enoside (7). When methanol was used in place of ether no appreciable ester formation took place but elimination of iodine and an acetoxy group occurred, accompanied by complete deacetylation of the remaining ester groups.

ISSN:0008-4042    

DOI:10.1139/v68-365

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Alkynethiolates, generated from 1,2,3-thiadiazoles by a strong base, react with alcohols and alkanethiols to give thioneesters and dithioesters respectively. In this manner were prepared: dimethyl monothionemalonate, (methoxythiocarbonyl)acetamide, methyl phenylthioneacetate, and ethyl phenyldithioacetate. 2,ω-Diphenyl-1,4-dithiafulvene results from the reaction between lithium 2-phenylethynethiolate and water.

ISSN:0008-4042    

DOI:10.1139/v68-366

出版商:NRC Research Press    

年代:1968

数据来源: NRC