Expeditious synthesis of sulfoazetidine spiro-C-glycosides from ketose acetals

Pyranoid and furanoid spiro-N-mesyl azetidines, a new type of water-soluble spiro-C-nucleoside, have been prepared from easily available sugar spiroacetals (or glycosyl cyanides). The synthetic pathway involves opening of the acetalic ring with trimethylsilylcyanide, reduction, formation of an N,O-dimesylate, cyclization with sodium hydride in anhydrous DMF, and O-deprotection.