Synthetic studies of proanthocyanidins. highly stereoselective synthesis of the catechin dimer, procyanidin-B3

Abstract

A stereoselective synthesis of benzylated procyanidin-B3, a condensed catechin dimer, is described. Condensation of 5,7,3′,4′-tetrabenzylcatechin with (2R,3S,4S)-5,7,3′,4′-tetrabenzyloxy-3-acetoxy-4-methoxyflavan as an electrophile in the presence of TiCl4 led to octabenzylated procyanidin-B3 stereoselectively. © 2002 by Japan Society for Bioscience, Biotechnology, and Agrochemistry.