Selective 3-O-allylation and 3-O-benzylation of methyl α-D-manno-, α-L-rhamno- and β-L-fuco-pyranoside

Article abstract of DOI:10.1016/0008-6215(91)84158-B

The selective 3-O-allylation or 3-O-benzylation of methyl glycosides is a very useful procedure in anhydro sugar synthesis and oligosaccharide synthesis, because it can substantially simplify the reaction pathways. The 'direct stannylation method'³, by which unprotected glycopyranosides were treated with dibutyltin oxide and then alkylated, was effective for the 3-O-allylation of methyl α- (ref. 1) and β-D-galactopyranoside, but 'gave a quantitative recovery of starting material' in the case of methyl α-D-mannopyranoside. We report here a slightly modified procedure for direct stannylation that successfully accomplishes the 3-O-allylation and 3-O-benzylation of methyl α-D-manno-, α-L-rhamno- and β-L-fuco-pyranoside.