Enantioselective synthesis of flavonoids. Part 3.1 trans- and cis-Flavan-3-ol methyl ether acetates

Abstract

Asymmetric dihydroxylation of a series of polyoxygenated 1,3-diarylpropenes with AD-mix-α or AD-mix-β in the presence of methanesulfonamide and subsequent acid-catalysed cyclization, affords for the first time synthetic access to trans- and cis-flavan-3-ol derivatives, essentially enantiopure and in good yield.