Syntheses of a partially benzylated derivative of the anhydro-d-altro-heptulose found in Coriaria japonica A and of its analogs

A partially benzylated derivative of anhydro-d-altro-heptulose found in Coriaria japonica A, which is a synthetically useful unit, was successfully synthesized from a d-mannose derivative by a novel synthetic approach involving the intramolecular O-ketopyranosylation reaction developed by us. This synthetic approach was also applicable to the preparation of its four analogs.