Synthesis of methyl d- and l-glycero-α-d-manno-heptofuranosides

Methyl l-glycero-α-d-manno- and d-glycero-α-d-manno-heptofuranosides (1 and 2) have been synthesized using two-carbon-atom elongation of a lyxofuranoside system. A new method for the synthesis of 2 has been developed based on the reaction of protected methyl α-d-manno-hexodialdo-1,4-furanoside with benzyloxymethylmagnesium chloride.