The cyanation reaction of O-acetylated S-glycosyl phosphorothioates

The reaction of α- and β-1-S-phosphorothioates of per-O-acetylated monosaccharides (galactose, xylose, glucose) with trimethylsilyl cyanide in the presence of boron trifluoride etherate has been investigated. It has been established that in dichloromethane 1,2-O-cyanoethylidene derivatives of aldoses are formed in high yields. When the reaction was carried out in acetonitrile, peracetylated galactosyl cyanide was formed as the major product.