ISSN:0030-4921    

DOI:10.1002/mrc.1270070414

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractThe chemical shifts of 4axand 4eqsubstituted adamantanones are compared with those calculated with the aid of a given additivity rule. It is found that both δ carbons are shielded with respect to the substituent. In contract to the situation for they‐atoms, however, the δsynatom is less shielded than the δantiatom. In most cases the additivity rule predicts the chemical shifts with an accuracy of approximately 1 ppm. Exceptions are carbon atoms 4 and 9 of the 4eqsubstituted adamantanones. In both cases the measured values are 4 to 6 ppm upfield. This can possibly be explained by an electronic interaction between the carbonyl group and the substit

ISSN:0030-4921    

DOI:10.1002/mrc.1270070402

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

Abstract1H NMR spectra are reported for Michler's ketone and twenty of its derivatives, along with13C chemical shifts for five of the compounds.1H chemical shifts show only small changes with increasing substitution at the sterically hindered 2‐position. Estimates of the dihedral angle between the benzene ring and CCOC planes have been obtained from the chemical shifts of CO and 4‐C for ketones1, 3, 5, 15and16. These angles are both internally consistent and very similar to dihedral angles determined by other methods for corresponding compounds in the benzopheno

ISSN:0030-4921    

DOI:10.1002/mrc.1270070403

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractLes déplacements chimiques des protons d'aroyl‐2 et ‐3 furannes (α‐thénoyle, α‐furoyle, benzoyle)1et2ont été interprétés en termes de conformations préférentielles et ont permis de comparer les énergies de conjugaison de ces différents groupements. Le groupe thénoyl‐2 conserve toujours une disposition OScisalors que le groupe furoyl‐2 ne possède aucune pr

ISSN:0030-4921    

DOI:10.1002/mrc.1270070404

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractL'étude des constantes de couplage stéréospécifiques4Jet5Jainsi que l'interprétation des déplacements chimiques en termes d'effets électroniques de substituants et d'anisotropie ont permis de montrer que les formyl‐2 aroyl‐3 furannes existent sous une conformation OOcisdes deux groupements carbonylés et les formyl‐3 aroyl‐2 furannes sous une confo

ISSN:0030-4921    

DOI:10.1002/mrc.1270070405

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractCarbon‐13 spin‐lattice relaxation times and chemical shifts are reported for a number of cyclic alcohols and the corresponding methyl ethers. The overall rotation of the alcohols was found to be considerably more anisotropic than that of the methyl ethers. Anisotropic motion becomes less pronounced in both series as ring size increa

ISSN:0030-4921    

DOI:10.1002/mrc.1270070406

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractL'effet d'inversion de l'azote sur les déplacements chimiques en Résonance Magnétique Nucléaire de carbone‐13 a été observé avec la diphényl‐2,2‐aziridine, la diméthyl‐2,2 diphényl‐3,3 aziridine et la phényl‐2 méthyl‐2 aziridine, sous des conditions d'échange lent du proton du NH. De plus, nous avons pu déceler des variations de déplacements chimiques dǔes à

ISSN:0030-4921    

DOI:10.1002/mrc.1270070407

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractThe1H NMR spectra of isomeric 5,6‐dimethyl‐2‐oxo‐1,4‐dioxans have been recorded and the pertinent chemical shifts and coupling constants determined. The parameters indicate that both isomers exist as an equilibrium mixture of interconverting half chair ring conf

ISSN:0030-4921    

DOI:10.1002/mrc.1270070408

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractThe carboxyl proton chemical shifts of neat trimethylacetic acid and its solutions in cyclohexane have been measured as a function of temperature. Formation, at the melting point, of a carboxyl group satellite line on the low field side has been found. The intensity of this satellite line rises with decreasing temperature, whereas the intensity of the main line decreases. The chemical shifts of the monomer (δm= 4·9 ± 0·6 ppm) and dimers, the equilibrium constants, enthalpy (ΔH= −(11·3 ± 0·6) kcal/mol) and entropy (ΔS= −(13·5 ± 0·7) cal/mol. degree) changes have been calculated using the concentration dependence of the chemical shifts of trimethylacetic acid in cyclohexane solutions at various temperatures. The chemical shift of the satellite line has been shown to correspond to the chemical shift of the cyclic dim

ISSN:0030-4921    

DOI:10.1002/mrc.1270070409

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY

摘要:

AbstractProton coupled carbon‐13 NMR spectra of eleven mono‐, di‐ and trimethylpyridines were analysed on a first order basis. The long range13C1H coupling constants are similar to those observed for pyridine and cyanopy

ISSN:0030-4921    

DOI:10.1002/mrc.1270070410

出版商:John Wiley&Sons Limited    

年代:1975

数据来源: WILEY