On the reaction of 4,6-O-benzylidene-2-deoxypyranosides with sodium cyanoborohydride: formation of 1,5-anhydroalditols

Abstract

Some methyl 4,6-O-benzylidene-2-deoxypyranosides were submitted to the action of sodium cyanoborohydride in acidic medium. Regiospecific cleavage of the benzylidene ring was observed, giving the expected 6-O-benzyl derivative. Depending upon the substitution at C-2 reductive cleavage of the aglycone was observed as a side-reaction or as a main reaction. This could provide a new entry to 1,5-anhydroalditols branched at C-2.