The detection and isolation of the rotational isomers of some phenanthridinium 5-vinyloxides
Abstract
The n.m.r. spectra of suitable 6-aryl- and 6-aralkylphenanthridinium 5-vinyloxides have shown that restricted rotation of the 5- and 6-substituents gives rise to pairs of diastereomeric rotamers and in one case both rotamers were isolated and characterised.