摘要:

Abstract17O NMR spectra have been obtained in the FT mode for some furan and isoxazole derivatives. The chemical shifts, mainly governed by the electronegativities of the atoms bonded to the central oxygen, are also affected by alkylation on the different positions of the ring systems, which gives rise to β and γ effects similar to those observed for simple aliphatic ether

ISSN:0030-4921    

DOI:10.1002/mrc.1270220112

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe NMR spectra of the diastereomeric complexes formed by the coordination of nitrogenous enantiomeric bases with cobalt(III)meso‐tetraphenylporphyrin (CoTPP) allow the immediate differentiation of these complexes. The spectra are interpreted on the basis of symmetry (RRandSS) and pseudo‐chirality (RSandSR) considerations. The effects are observed in both the proton and carbon spectra and the complexes are stable in both CDCl3and DMSO‐d4solution. This technique, in principle, allows the ready determination of the optical purity of multifunctional li

ISSN:0030-4921    

DOI:10.1002/mrc.1270220113

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractA full assignment of the13C signals of four pentacyclic triterpenes confirms the results obtained by1H NMR analysis of steroidal methyls, resolving the stereochemistry of the oxidation product of 3‐β‐acetoxyolean‐12‐en‐30‐oic acid

ISSN:0030-4921    

DOI:10.1002/mrc.1270220114

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

ISSN:0030-4921    

DOI:10.1002/mrc.1270220101

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY