A regioselective reductive ring opening of 4,6-O-prop-2-enylidene acetals of hexopyranosides

Abstract

The 4,6-O-prop-2-enylidene acetals (1)–(3) on reductive cleavage with sodium cyanoborohydride–hydrogen chloride in tetrahydrofuran yield the 6-O-prop-2-enyl ethers (4), (6), and (7) in good yield. The reduction is thus compatible with the presence of glycosidic bonds, benzyl, benzoyl, and acetamido-groups and gives ready access to protected hexopyranosides with free 4-hydroxy-group.