摘要:

AbstractX‐Ray data for inherently dissymmetric D,L‐trans‐1,2,3,4,1′,2′,3′,4′‐octahydro‐4,4′‐biphenanthrylidene are presented; the molecular symmetry isC2. Small double‐bond torsion and twist boat cyclohexene conformation

ISSN:0165-0513    

DOI:10.1002/recl.19790980102

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractAttempts were undertaken to prepare 9‐stibaanthracene (2c) and its 10‐phenyl derivative (3c). Both compounds proved to be too unstable for isolation; their possible occurrence as intermediates is discussed brie

ISSN:0165-0513    

DOI:10.1002/recl.19790980103

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractEvidence is presented by means of15N‐labelling that the occurrence of anSN(ANRORC) mechanism in the amino‐dehalogenation of 4‐substituted 6‐halogenopyrimidines by potassium amide in liquid ammonia is dependent on at least two factors. The C(2) position must be readily accessible to the attacking amide ion and the substituent at C(4) must not contain an acidic hydrogen atom adjacent to the pyrimidine nucleus. It is shown that the amount to which anSN(ANRORC) process occurs can be dependent on the reaction temp

ISSN:0165-0513    

DOI:10.1002/recl.19790980104

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractVCl3is able to bind dinitrogen at room temperature and a N2pressure of 1 atmosphere after reduction with Li+Np−(Np = naphthalene) or with Li + Li+Np2−. In the latter case also a direct reaction of N2with Li + Li2+Np2−occurs, so that there are two independent nitrogen fixation reactions effective in the system VCl3+ Li + Li2+Np2−. The role of Np2−ions in this system has been investigated and a proposal for the mechanism of the reaction of Li + Li2+Np2−wit

ISSN:0165-0513    

DOI:10.1002/recl.19790980105

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractCNDO/2 calculations are reported on four caged phosphorus compounds, Y‐P(OCH2CH2)3X (X = N, CH; Y = O, OH+, H+). Structures with and without a transannular bond between P and X were taken into account; the influence of this bond on the stability of the compounds was examined. For X = N and Y = H+the lowest‐energy structure corresponds with the geometry found by X‐ray analysis. If X = CH, formation of a transannular bond proves to be unlikely, as expected. The calculations predict the formation of a P‐N bond upon protonation of the phosphate (X = N, Y = O). The net atomic charges in the protonated phosphite were used to calculate its NMR coupling constant,1JPH, which correlates well with the value found experim

ISSN:0165-0513    

DOI:10.1002/recl.19790980106

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

Abstract3‐Methyl‐2‐chloro‐2‐hydroxy‐2‐phosphanaphthalene (3) is obtained from the dihydroprecursors6and14by treatment with COCl2followed by triethylamine. Contrary to other P‐hydroxy‐λ5‐phosphorins,3is thermally surprisingly stable. Protons catalyze its rearrangement to the thermodynamically more stable isomer 3‐methyl‐2‐chloro‐1,2‐dihydro‐2‐phosphanaphthalene 2‐oxide (5). Some aspec

ISSN:0165-0513    

DOI:10.1002/recl.19790980107

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractReaction of α‐chloro nitroso compounds with tetramethylallene gives rise to the formation of hitherto unknown crystalline cross‐conjugated nitrone hydrochlorides3, which can be converted into free nitrones4upon treatment with liquid ammonia. The reaction between 2‐chloro‐2‐nitrosoadamantane and 3‐phenyl‐1,2‐butadiene proceeds equally well, but with other α‐chloro nitroso compounds and with other alkylallenes only complicated mixtures are obtained, which contain the corresponding nitrone hydrochlorides as judged from hydrolysis t

ISSN:0165-0513    

DOI:10.1002/recl.19790980108

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractBromination of the methyl ortho esters1a‐iin liq. SO2at −80°C gives rapidly the dimethoxycarbenium bromides2a‐itogether with methyl hypobromite. The aliphatic bromides2a‐gdisplay two distinct methoxyl NMR absorptions, suggesting a “cis‐trans” configuration. The aromatic bromides2h‐ishow only one methoxyl absorption, which can be explained by assuming the symmetrical “cis‐trans” conformation of the aryldimethoxycarbenium ion.The bromides1a‐iare stable up to −50°C and are converted into the corresponding methyl ester5and methyl bromide6at higher temperatures. During the thermal decomposition of2a‐iline broadening of the methoxyl absorptions are observed, either due to rotation of the methoxyl groups around the C‐O bonds in the dimethoxycarbenium ionDand/or by a rapid equilibrium betwee

ISSN:0165-0513    

DOI:10.1002/recl.19790980109

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19790980101

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY