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

Treatment of tri-O-acetyl- -glucal11 with several alcohols in the presence of catalytic amount of POM (K5CoW12O40•3H2O) 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.