Spectral evidence for the formation of quinone methide intermediates from 5- and 7-hydroxyflavonoids
作者:Michael R. Attwood、Ben R. Brown、Stephen G. Lisseter、Christopher L. Torrero、Philip M. Weaver
DOI:10.1039/c39840000177
日期:——
The u.v. spectra of 5-and 7-hydroxyflavan-4-ols in acid solution are interpreted in terms of the π-π* transition of quinonemethideintermediates; the enhanced reactivity of 4-substituted 7-hydroxyflavans compared to 4-substituted 7-methoxyflavans supports this mechanism which may be operative in the biozynthesis of polyflavonoids (e.g. condensed tannins).