Condensed tannins: a proposed route to 2R,3R-(2,3-cis)-proanthocyanidins
Abstract
The biogenesis of 2R,3R-(2,3-cis)-proanthocyanidins from 2R,3R-(2,3-trans)-dihydroflavonols can be accounted for by tautomerism between quinone methide and flav-3-en-3-ol intermediates.