摘要:

AbstractWhereas pyruvic acid smoothly decarboxylates in the vapour phase to give acetaldehyde, methyl pyruvate is much more stable. Between 440 and 480°, carbon monoxide is eliminated leading to methyl acetate.In an excess of toluene,allylpyruvate reacts much faster than the methyl ester, giving large proportions of CO2, CO and CH4; 4‐phenyl‐1‐butene and bibenzyl are also important products. Decomposition thus resembles that of allyl acetate11. However, the pyruvate reacts some thousand times more rapidly, the activation energy being 12 kcal · mole−1lower. This suggests the first step of allyl pyruvate breakdown to be amultiple fissioninto acetyl, CO2and allyl. Analogously, benzyl pyruvate decomposes much faster than the corresponding acetate.In an Appendix, kinetic data on allyl and benzyl esters are discussed on the basis of ‐ known or derived ‐ heats of formation; it would appear that consistency is not always

ISSN:0165-0513    

DOI:10.1002/recl.19670861002

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe “γ”‐thiopyran‐1,1‐dioxide, described previously1,2, has proved to be α‐thiopyran‐1,1‐dioxide, as was definitely established by an X‐ray diffraction study as well as by the synthesis of the α‐isomer b

ISSN:0165-0513    

DOI:10.1002/recl.19670861003

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe optical rotatory dispersion spectra of the enantiomers of β‐methoxyvaline were measured between 200 and 400 nm. From the Cotton effect at 210 nm follow the absolute configurations, and consequently those of the derived hydroxy amino acids:D‐(‐)‐ andL‐(+)‐β

ISSN:0165-0513    

DOI:10.1002/recl.19670861004

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19670861005

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19670861006

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractNMR spectra of solutions containing norbornadiene (N) and μ‐dichloro dirhodium dinorbornadiene (Rh2N2Cl2) at low temperatures (<− 40°C) show the presence of a new species, a five‐coordinated rhodium dinorbornadiene chloride (RhN2Cl). It is formed according toRh2N2Cl2+ 2 N ⇌ 2 RhN2Cl.At higher temperatures (−40° to + 100°C) line broadening is observed, indicating the occurrence of rapid exchange processes. From the data the following mechanism is deduced: a slow reaction (by one or two steps) of the dimeric complex with one mole of NRh2N2Cl2+ N ⇌ RhN2Cl + RhNCl,and a subsequent fast reaction yielding a second mole of RhN2ClRhN

ISSN:0165-0513    

DOI:10.1002/recl.19670861007

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractVarious compounds with the system and have been converted into conjugated trienes by means of potassiumtert‐butoxide in dimethyl sulfoxide (DMSO). Aromatization has been observed with compounds possessing the system

ISSN:0165-0513    

DOI:10.1002/recl.19670861008

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe chlorination of naphthalene shows an inverse deuterium isotope effect, the reaction of naphthalene being slower than that of octadeuterionaphthalene by a factor of 0.85. The product‐forming stages are also subject to a deuterium isotope effect which influences the partitioning between addition and substitution; the most direct interpretation of the results is that the values ofkH/kDfor the stages of proton‐loss are subject to a normal deuterium isotope effect, withkH/kD

ISSN:0165-0513    

DOI:10.1002/recl.19670861009

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThis paper describes systems of mono‐ and di‐valent metal chlorides with antimony pentachloride in methyl cyanide. The Cl−‐ion transfer, which occurs between the chlorides and antimony pentachloride in solution, has been studied conductometrically. This transfer is discussed on the basis of electrostatic theory.In the solid state, complexes of the types M+1(CH3CN)xSbCl6−and M2+(CH3CN)y(SbCl6−)2are isolated. The mono‐ and di‐valent metal ions are solvated by the methyl cyanide molecules. Magnetochemical measurements indicate that the divalent transition metal ions are surrounded octahedrally by six methyl cy

ISSN:0165-0513    

DOI:10.1002/recl.19670861010

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractA number of complexes with the general formula M(CH3CN)n(anion)m, is reported. The anions are SnCl62−and (SnCl5· CH3CN)−. The cations M are the monovalent ions: Li, Na, Cu, (C2H5)4N, and the divalent ions: Be, Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Cu, Zn. Most of the cations are completely solvated by the methyl cyanide in these complexes.The compounds were synthesized by reaction of SnCl4with the metal chlorides in methyl cyanide. In some cases this chloride‐ion transfer was studied spectrophotometrically and conductometrically. The ligand‐field splitting parameter (Dq) and Racah parameter (B) are calculated for some M(CH3CN)62+ions.Several complexes proved to be isomorphous from their X‐ray powder‐patterns. Information about the structure of the anions was obtained from far‐infrared and Raman spectra. The ternary phase‐diagram CoCl2‐SnCl4

ISSN:0165-0513    

DOI:10.1002/recl.19670861011

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY