MONOALKYLATION OF TRIBUTYLTIN ACTIVATED METHYL 4,6-O-BENZYLIDENE-ALPHA-D-GLUCOPYRANOSIDE AND 4,6-O-BENZYLIDENE-ALPHA-D-GALACTOPYRANOSIDE

Mono alkylation of methyl 4,6-O-benzylidene-alpha-D-gluco - and galact opyranosides could be carried out in good yields using bis(tributyltin ) oxide. Regioselectivity, giving predominant 2-substitution, was exce llent in the case of D-glucopyranoside. The ratio of the tin reagent t o that of the substrate seems to be critical in determining the yield and the extent of regioselectivity. Alkylation could also be carried o ut in solvents at a slower rate, using less reagent, but the regiosele ctivity was lower.