ISSN:0030-4921    

DOI:10.1002/mrc.1270050915

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

ISSN:0030-4921    

DOI:10.1002/mrc.1270050916

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

ISSN:0030-4921    

DOI:10.1002/mrc.1270050918

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractEs Werden die1H‐ und31PNMR‐Spektren der Dimethylamino methylen‐phosphoranemitgeteilt und ein einfaches Herstellungsverfahren für4bes

ISSN:0030-4921    

DOI:10.1002/mrc.1270050902

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractSpin information should be passed most effectively from a carbon‐hydrogen bond to thep‐rich carbon‐carbon bond of an adjacent cyclopropane ring when the two bonds are parallel. The existence of such a mechanism is tested in a series of spiro hydrocarbons and epoxides in which four‐bond zigzag (W) couplings are absent. The structure is varied from the ideal parallel‐orbital geometry of spirohexane and the homologous epoxide to the unfavorable staggered‐orbital geometry of spiro[2·5]octane and its epoxide. In the parallel‐orbital situation, a four‐bond non‐W coupling of about 0·2 Hz is found; this coupling is absent in the other geometric situations. The meager ability of the cyclopropyl bonds to pass spin information, when compared to the π‐orbitals in alkenes, is discussed in terms of the electronic stru

ISSN:0030-4921    

DOI:10.1002/mrc.1270050903

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractLe spectre de RMP de quelques nouveaux oxazaphosphorinanes‐1,3,2 est analysé. Dans un cas, après élimination du couplage entre les protons et le phosphore, on a affaire à un système ABKLXY particulier dans lequel certaines constantes de couplage entre protons vicinaux sont nulles. Le système ABKLXY oùJAK=JAL=JBK=JBLest étudié, ce qui permet d'accéder à la plupart des paramètres du composé considéré. La conformation du cycle est précisée, la valeur de l'enthalpie libre conformationnelle est donnée et, pour l'oxazaphosphorinane‐1,3,2 précédent, l'angle de torsion des liaisons C

ISSN:0030-4921    

DOI:10.1002/mrc.1270050904

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractThe NMR spectra of a series of chiral propionamides have been determined in D(+)1‐phenylethylamine solution. The α‐methine protons of the propionic acid moiety in the propionamide enantiomers were found to be anisochronous in this solvent. The sense of non‐equivalence of these protons was found to be the same for all members of a homochiral series. The chemical shift difference between their signals was demonstrated to be dependent upon the temperature and concentration of the solution. A method is described whereby the enantiomeric purity of the amides could be calculated from these signals in cases where the position of the baseline in their spectra was u

ISSN:0030-4921    

DOI:10.1002/mrc.1270050905

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractAn aromatischen Nitrilverbindungen der allgemeinen Strukturpara‐YC6H4XCN mit X = O, S, Se und N(CH3) wurden die13C‐NMR‐ sowie für X = O die14N‐NMR‐und für Y = F die19F‐NMR‐chemischen Verschiebungen bestimmt. Die Meßergebnisse wurden in Zusammenhang mit der elektronischen Struktur der Moleküle (Substituentenkonstanten, π‐Elektronendichten i

ISSN:0030-4921    

DOI:10.1002/mrc.1270050906

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

AbstractThe interactions of trimethylaluminium and dimethylaluminium chloride with some methyl‐substituted pyridines have been investigated in dichloromethane by means of temperature‐dependent proton NMR spectra. 4‐Methylpyridine forms 1:1 addition complexes with trimethylaluminium and dimethylaluminium chloride. 2,6‐Dimethyl‐ and 2,4,6‐trimethylpyridines have been found to yield three types of complex with dimethylaluminium chloride, however, and only one type of complex with trimethylaluminium. The configurations of the complexes in solution, and exchange equilibria between methylaluminium compounds and 2,6‐dimethylpyridine are a

ISSN:0030-4921    

DOI:10.1002/mrc.1270050907

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY

摘要:

Abstract4J(HH)‐Kopplungen in die beiden stereoisomeren 3‐Chlor‐2,3‐dibrombuttersäuremethylester wurden in fünf Lösungsmitte

ISSN:0030-4921    

DOI:10.1002/mrc.1270050908

出版商:John Wiley&Sons Limited    

年代:1973

数据来源: WILEY