Regioselective oxidative cleavage of benzylidene acetals of glycopyranosides with periodic acid catalyzed by tetrabutylammonium bromide

Abstract

International audienceA combination of periodic acid, tetrabutylammonium bromide, and wet alumina in dichloromethane efficiently oxidized benzylidene acetals of carbohydrates to the corresponding hydroxybenzoates in excellent yields (>90%). Under these conditions, other protecting groups, such as tert-butyl(dimethyl)silyl, tert-butyl(diphenyl)silyl, and functional groups, such as epoxide, were unaffected. By varying the nature of the protecting group at the C3 position, good to high regioselectivity toward 4- or 6-benzoates was obtained