A Novel Glycosylation of 3-Deoxy-D-glycero-D-galacto-2-nonulosonic Acid (KDN) via in Situ Pyranose-Furanose Rearrangement

Abstract

In studies on the glycosylation of 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) derivatives, O-glycosides of furanose-type KDN were synthesized from benzyl 4, 5, 7, 8, 9-penta-O-acetyl-2-bromo-2, 3-dideoxy-D-glycero-D-galacto-2-nonulopyranosonate under Koenigs-Knorr reaction conditions. The furanoid structures of the KDN moiety were supported by with ¹H-NMR experiments, and the reaction was considered as a novel glycosylation with ring contraction, which proceeded via in situ pyranose-furanose rearrangement of the KDN moiety, and subsequent coupling with acceptors.