EASY SYNTHESIS OF 1-ALLYL-1-DEOXY-β- AND α- d-LYXOFURANOSES

2,3;5,6-Di-O-isopropylidene-α-d-mannofuranosyl chloride reacted with allylmagnesium bromide with preferential inversion of the anomeric configuration to furnish a mixture of the 1-allyl-1-deoxy-β- and α-d-mannofuranoses. Separation of β and α derivatives was possible only after conversion to the 1-allyl-1-deoxylyxofuranoses 2 and 3. The β configuration of the predominant product 2 was proved using the NOE method.