Structural influences on the isomerization of 4-benzyl- and 4-allyl-1,2-naphthoquinones to quinonemethides and their stereochemistry
Abstract
The isomerization of 4-benzyl-1,2-naphthoquinones and 4-allyl-1,2-naphthoquinones to quinonemethides has been studied. The steric interaction and extra π conjugation in the quinonemethide, and acidity of methylene protons of the quinone, are controlling factors for the isomerization. 1H N.m.r. studies suggested that the quinonemethides have the E configuration.