Magnesium perchlorate: Highly efficient and versatile catalyst for the ferrier glycosylation reaction

Alkyl and aryl 2,3-unsaturated glycosides have been prepared by the reaction of alcohols or thiols with 3,4,6-tri-O-acetyl-D-glucal in acetonitrile at room temperature in the presence of a catalytic amount of magnesium perchlorate. Similarly, glycals have shown to react smoothly with silyl nucleophiles such as trimethylsilyl azide, allyltrimethylsilane, trimethylsilyl cyanide and in the presence of a catalytic amount of magnesium perchlorate to give the corresponding 2,3-unsaturated glycosyl azides, allyl glycosides, and glycosyl cyanides in excellent yields with high a-selectivity. Use of economically convenient catalyst, mild reaction conditions, operational simplicity, high yields and short reaction times are the important features of the present protocol.