Configurations and conformations in acyclic, unsaturated hydrocarbons. A 13C NMR study

J.W. Haan, de, L.J.M. Ven, van de

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

216 Citaten (Scopus)
3 Downloads (Pure)

Samenvatting

13C NMR (CMR) spectra of a number of di- and trisubstituted ethylenes have been measured. Very consistent values are found for the differential shieldings of allylic carbons in a number of linear, (Z)- and (E)-disubstituted ethylenes. The discrepancies between the several structural elements are explained tentatively by assuming different rotational preferences in the (Z)-isomers, the (E)-isomers, or both. The results obtained for some branched olefins are qualitatively in agreement with conclusions reached in previous 1H NMR (PMR) investigations, with the possible exception of 2,5-diMe-3-hexene. Differential shieldings in trisubstituted ethylenes are larger than in disubstituted ethylenes, probably as a consequence of steric interaction between geminal substituents. It is confirmed, that API's recent relabelling of the isomers of 3-Me-2-hexene was justified. Furthermore, the (E)-configuration is assigned to the high-boiling isomer of 3,4,4-triMe-2-pentene. On the other hand, the high-boiling isomer of 3-Et-4-Me-2-pentene is shown to be the (Z)-isomer. For the isomeric pair of geraniol and nerol, the (E)-configuration is assigned to the former and the (Z)-configuration to the latter, in agreement with our recent PMR investigations.
Originele taal-2Engels
Pagina's (van-tot)147-153
Aantal pagina's7
TijdschriftOrganic Magnetic Resonance
Volume5
Nummer van het tijdschrift3
DOI's
StatusGepubliceerd - 1973

Vingerafdruk

Duik in de onderzoeksthema's van 'Configurations and conformations in acyclic, unsaturated hydrocarbons. A 13C NMR study'. Samen vormen ze een unieke vingerafdruk.

Citeer dit