First Total Syntheses Of Two Natural Glycosides

Isosyringinoside (1) and 3-(O-beta-(D)-glucopyranosyl)-alpha-(O-beta-(D)-glucopyranosyl)-4-hydroxy phenylethanol (2), the natural bioactive compounds contained unique structures, were first totally synthesized using easily available materials in short convenient routes with overall yields of 20.2% and 27.0%, respectively. An efficient total synthesis of 1 was developed in six steps, which contained two key steps of highly regioselective glycosylation without any selective protection steps. The seven-step synthesis of 2 involved two steps of regioselective glycosylations using BF3-O(C2H5)(2) and TMSOTf as catalysts, respectively.