ISSN:0030-4921    

DOI:10.1002/mrc.1270060818

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

ISSN:0030-4921    

DOI:10.1002/mrc.1270060819

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractDie dominierende Konformation einiger 1,4:3,6‐bis(Thioanhydro)‐D‐idit Derivate (1abis1c) wurde durch1H NMR Untersuchungen bestimmt. Weiterhin konnte auch die Konfiguration und Konformation des durch Oxydation aus 2,5‐Di‐O‐acetyl‐1,4:3,6‐bis(thioanhydro)‐D‐idit (1b) hergestellten symmetrischen (3) und asymmetrischen (4) Disulfoxyds, sowohl die des Disulfons (5

ISSN:0030-4921    

DOI:10.1002/mrc.1270060802

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractCarbon‐13 chemical shifts of sixteen monosubstituted ethylenes were obtained. In order to explain the chemical shifts, σ and π electron densities of these compounds are calculated by the σ‐included ω‐HMO method.See Ref. 8.A linear relationship exists between carbon‐13 chemical shifts and the calculated electron densities, and also between substituent constants and electron densities. A slope of unity is obtained between the chemical shifts of α carbons of monosubstituted ethylenes and those of carbons adjacent to the substituents in monosubstituted benzenes. On the other hand, a plot of chemical shifts of Corthoof benzene derivatives against that of the β carbon in ethylene derivatives gives a slope of 3. These slopes can be explained by the calculated electron densities. A slope of 4/3 is obtained between the direct coupling constant1J(CH) of the α carbon in monosubstituted ethylenes and that in the corresponding subs

ISSN:0030-4921    

DOI:10.1002/mrc.1270060803

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractDes expériences d'INDOR effectuées sur le β‐hydroxyphosphonate esterRS,RSen solution dans le (CD3)2CO ou (CD3)2SO montrent que le couplage4J(PCCOH) est positif. La valeur plus élevée de ce couplage dans (CD3)2SO que dans (CD3)2CO indique qu'une géométrie en W rend le coupl

ISSN:0030-4921    

DOI:10.1002/mrc.1270060804

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractDie ESR‐Spektren von Radikalen in Lösung, die durch elektrolytische Reduktion dinuclearer und trinclearer Polymethincyanin‐Farbstoffe erhalten wurden, werden interpretiert. Aus den Werten der Kopplungskonstanten lassen sich Aussagen über die Konformation der Radikale gew

ISSN:0030-4921    

DOI:10.1002/mrc.1270060805

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractThe13C NMR chemical shifts and one‐bond carbon–hydrogen coupling constants have been obtained for the title compounds in carbon disulphide as solvent. There appears to be little solvent effect on the13C chemical shifts. The results suggest the order of release of electrons into the ring is O ≫

ISSN:0030-4921    

DOI:10.1002/mrc.1270060806

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractEine Zuordnung der13‐Resonanzfrequenzen von β‐Carotin gelingt als Grenzwert einer Serie von Apocarotinalen mit wachsender Kettenlänge. Dadurch erhält man genauen Einblick in die abklingende Polarisierung der Doppelbindungen mit wachsendem Abstand von der Carbonylgruppe und mit Hilfe der Relaxationszeiten in die Beweglichkeit des Mo

ISSN:0030-4921    

DOI:10.1002/mrc.1270060807

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractThe energy difference (ΔE) between the two types of rotamers of β‐methoxyethylmercuric chloride has been satisfactorily determined by only assuming the ratio of vicinaltransandgaucheHH coupling constants. The validity of the result was confirmed by the large temperature dependence of the vicinal HgH couplings in various solvents. Moreover, it has become possible to determine small values of ΔEin nonpolar solvents. Two ΔEvalues of β‐methoxypropylmercuric chloride in various solvents were determined on the basis of the substituent electronegativity effect on the HH couplings and their validity was supported by the large temperature dependence of the vicinal HgH couplings. With regard toerythro‐ andthreo‐(α‐methyl‐β‐methoxy)propylmercuric chlorides, both the HH and HgH couplings were used to estimate the values of ΔEamong the rotamers. Throughout the mercury compounds, it was ascertained that the more polar the solvent, the greater the preference for the conformation with thetransdisposed HgCl and OCH3groups. Excellent agreement between the observed facts and the calculations by extended Hückel theory were shown with regard to the relative magnitude of the rotamer polarity and the conformational energy dif

ISSN:0030-4921    

DOI:10.1002/mrc.1270060808

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY

摘要:

AbstractThe preferred solute conformation of ethyl 3α‐phenyltropane‐3β‐carboxylate hydrochloride, the tropane analogue of pethidine, is shown to be a piperidine chair with an axial 3‐phenyl substituent by analysis of its1H NMR characteristics and spectral comparisons with model compounds. Conformational studies of synthetic intermediates are also reported and favoured boat forms identified for 3α‐diphenylhydroxymethyl‐3β‐tropanol and 3α‐phenyl‐3β‐tropanyl phenyl ketone. In the hot‐plate test for analgesia performed on mice, ethyl 3α‐phenyltropane‐3β‐carboxylate is about

ISSN:0030-4921    

DOI:10.1002/mrc.1270060809

出版商:John Wiley&Sons Limited    

年代:1974

数据来源: WILEY