Stereospecific Synthesis of D-Glycero-D-ido-oct-2-ulose

Summary.  D-Glycero-D-gulo-heptose reacted with 2,2-dimethoxypropane to give its 2,3:6,7-di-O-isopropylidene derivative. Its base-catalyzed addition to formaldehyde resulted in the formation of 2,3:6,7-di-O-isopropylidene-2-C-(hydroxymethyl)-D-glycero-D-gulo-heptofuranose. After acid hydrolysis of this aldolization product, a new branched-chain aldose, 2-C-(hydroxymethyl)-D-glycero-D-gulo-heptose, was obtained, which was stereospecifically rearranged under the catalytic action of molybdic acid to D-glycero-D-ido-oct-2-ulose. Received October 17, 2000. Accepted December 4, 2000