Homologation of methyl 2-azido- and 2-acetamido-3,4-di-O-benzyl-2-deoxy-d-hexopyranosides with allyloxymethylmagnesium chloride

Methyl 2-azido-2-deoxy-hexodialdo-1,5-pyranosides of the α-, β-d-gluco and α-d-manno configuration as well as methyl 2-acetamido-2-deoxy-hexodialdo-1,5-pyranosides of the α- and β-d-gluco configuration, protected at positions 3 and 4 with O-benzyl groups were reacted with an excess of allyloxymethylmagnesium or (phenyldimethylsilyl)methylmagnesium chlorides to afford mixtures of C-6 stereoisomeric heptopyranosides. Configuration of the products separated by column chromatography was assigned by 1H NMR data.