Efficient syntheses of beta-cyanosugars using glycosyl iodides derived from per-O-silylated mono- and disaccharides.

[reaction: see text] Reported herein is a general method for the efficient syntheses of a variety of beta-cyano glycosides through the activation of per-O-trimethylsilyl glycosides with TMSI to form alpha-glycosyl iodides, which undergo S(N)2-type displacement when treated with tetrabutylammonium cyanide. The cyanoglycosides were reduced under mild conditions using NaBH(4) in the presence of catalytic CoCl(2)(H(2)O)(6) in THF/H(2)O to give the corresponding aminomethyl glycosides.