A mild, efficient and α-selective glycosidation by using potassium dodecatungstocobaltate trihydrate as catalyst

Abstract

Treatment of tri- O-acetyl- d-glucal 1 3,4,6-Tri- O-acetyl-1,5-anhyro-2-deoxy- d-arabinahex-1-enitol. 1 1 with several alcohols in the presence of catalytic amount of POM (K 5CoW 12O 40·3H 2O) as a heterogeneous, reusable, efficient and environmentally benign catalyst under neutral conditions and ambient temperature gave the corresponding 2,3-unsaturated glycopyranosides in excellent yields, with good anomeric selectivity. This catalyst proved to be not efficient for phenols.