The synthesis of the epimeric 6C-butylglucoses from D-glucuronolactone is reported. The sodium borohydride reduction of two fully protected lactols is highly stereoselective but is accompanied by migration of a silyl protecting group; in the presence of cerium(III) chloride, there is little change in the stereoselectivity but the migration of the silyl group is suppressed. 6R-6C-Methylglucose and 6R-6C-butlylglucose are both better inhibitors of phosphoglucomutase than their 6S epimers.
