Three 1,6-anhydro-β-D-glycopyranose derivatives

Abstract

Two of the title compounds, 1,6-anhydro-2,3-O-(S)-benzylidene-beta-D-mannopyranose, C(13)H(14)O(5), (I), and 1,6-anhydro-4-O-benzyl-beta-D-mannopyranose, C(13)H(16)O(5), (II), are derived from beta-D-mannopyranose, while the third, 1,6-anhydro-3,4-O-(S)-benzylidene-beta-D-galactopyranose, C(13)H(14)O(5), (III), is derived from beta-D-galactopyranose. In the crystal packing, each hydroxyl group is involved in O-H.O hydrogen bonds, where the acceptor group is the other hydroxyl group in (II), or the endocyclic O atoms of the dioxolane [in (I)], anhydro [in (II)] or pyranose [in (III)] rings. Differences in the crystal packing arise from the contrasting O--H...O hydrogen-bonding environments.