摘要:

AbstractDiphenylketene (I) may be dimerized to forma. a cyclobutadione (IIa)1;b, a β‐lactone (IIb)2. Evidence is presented to suggest that a third dimer has the structure 1,3‐dioxo‐2,2,4‐triphenyltetralin (IIc). This compound reacts with (I) to produce a trimer (III), presumably the diphenylacetic ester of the enol form of IIc. Two compounds reported in the literature as diphenylketene dimers have been demonstrated to be 2,3‐diphenylindole and the ester, 2,3,4‐triphenylnaphthyl dip

ISSN:0165-0513    

DOI:10.1002/recl.19650840802

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractOpen chainα,β‐unsaturated ketones in solution show rotational isomerism. The infrared spectra ofcis‐benzal ketones indicate that one conformation is predominant. To obtain more insight into the nature of this conformation the dipole moments of a number ofcis‐ andtrans‐benzal ketones were determined. The data suggest that in thecis‐isomer the carbonyl group is considerably twisted out of the plane of the

ISSN:0165-0513    

DOI:10.1002/recl.19650840803

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe heats of solution of 18 alkali halides in anhydrous formamide at concentrations of about 0.01 molal and at 25° have been measured with an adiabatic calorimeter. Some physical properties of formamide have been determined. By applying the extendedDebije‐Hückeltheory the enthalpies of solution at infinite dilution were calculated. The difference in enthalpies of solution of the fluorides, chlorides, bromides and iodides, respectively, in water and in formamide appeared to be a constant, independent of the cation. An explanation in terms ofvan Eck'stheory of ionic solvation is gi

ISSN:0165-0513    

DOI:10.1002/recl.19650840804

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractWhen R2≠ R3,cis/transisomerism exists in trisubstituted ethylenes R1HC = CR2R3. A previously1described and tested concept of rehybridization makes possible the prediction of certain infrared frequency shifts as a function of sterical hindrance. In this paper it is shown that rehybridization accounts also reasonably well for certain frequency shifts of thosetri‐alkylated ethylenes wherecis/transisomerism is absent. A number of rules are then developed which make possible the assignment of thecisortransconfiguration when such isomerism is present.It is proposed that thecis/translabelling of the National Bureau of Standards' standard samples of the 3‐methyl‐2‐pentenes and 3,4‐dimethyl‐2‐pentenes be reversed. The geranyl group is given thecisconfiguration and neryl the correspondingtransconfiguration, contrary to the hitherto accepted structures. The Δ4(trans, Δ6 (7)(cis)structure has been assigned to the high‐boiling alloocimene and theall‐transconfiguration to the correspondi

ISSN:0165-0513    

DOI:10.1002/recl.19650840805

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractSelective alkylation of 1 or 8 hydroxyl as 1,3‐dihydroxy‐ or 3,8‐dihydroxyxanthone is rec

ISSN:0165-0513    

DOI:10.1002/recl.19650840806

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe mechanism of the base‐catalysed isomerization of theβγ‐unsaturated ketones isomesityl oxide and Δ5‐cholestenone to theirαβ‐unsaturated isomers was studied. The results are interpreted on the basis of a reaction scheme in which a dienolate anion, formed by deprotonation of the starting material, is an intermediate. The factors determining the rate of deprotonation of unsaturated ketones are discussed.Methoxide ions were found to deprotonate both ketones studied, whereas triethylamine, which deprotonates isomesityl oxide directly, was found to react with Δ5‐cholestenone only via the intermediate formation of methoxide ions from the s

ISSN:0165-0513    

DOI:10.1002/recl.19650840807

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractFrom double layer capacity measurements the fractional surface coverage of 1‐hexanol, thymol, polyoxethylene lauryl ether and sodium dodecyl sulfate is determined at different potentials. It appears that the fractional surface coverage, defined in terms of the integral capacity, does not change with potential within the range ‐0.20 to ‐1.00 V against the

ISSN:0165-0513    

DOI:10.1002/recl.19650840808

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19650840809

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe reaction of phenanthrene with bromine in methanol as a solvent has been studied. The composition of the rather complex reaction mixture as a function of reaction time has been determined by infrared spectrophotometry. The main reaction products appeared to betrans‐9,10‐dibromo‐9,10‐dihydrophenanthrene, 9‐bromo‐10‐methoxy‐9,10‐dihydrophenanthrene, 9‐methoxyphenanthrene, 10‐bromo‐9‐phenanthrone dimethyl acetal and 10,10‐dibromo‐9‐phenanthrone. The results of this investigation indicate that the bromide ion completing the addition of bromine to the 9,10‐double bond of phenanthrene, is tak

ISSN:0165-0513    

DOI:10.1002/recl.19650840810

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe present investigation deals with the effect of the number ofortho‐ethyl andortho‐isopropyl substituents on the stability of diarylmethyl radicals. These diarylmethyls were obtained by halogen abstraction from the correspondingly substituted benzhydryl chlorides.If not allorthopositions of the diarylmethyl carried ethyl or isopropyl groups, complete dimerization led to a symmetrical tetra‐arylethane; if all four positions were occupied by ethyl groups an equilibrium was reached between the radical and the dimer, while diarylmethyls with fourortho‐isopropyl groups showed no dimerization at all. Radicals of the last type were prone to disproportionation,

ISSN:0165-0513    

DOI:10.1002/recl.19650840811

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY