Arylboronic Acid-Mediated Glycosylation of 1,2-Dihydroxyglucoses

We explored direct dehydrative coupling of tetrahydro-2H-pyran-2,3-diol or a 1,2-dihydroxy sugar with various alcohols using a range of arylboronic acids.Among the catalysts, 2-borono-4-trifluoromethylbenzoic acid efficiently promoted acetalization of tetrahydro-2H-pyran-2,3-diol.Ferroceniumboronic acid showed the best catalytic activity for glycosylation of the 1,2-dihydroxy sugar.The major products were 1,2-cis-α-D-glucopyranosides.