Total Synthesis of 3-Deoxy-d-manno-2-octulosonic Acid (KDO) and 2-Deoxy-β-KDO

Abstract
Total syntheses of KDO and 2-deoxy-β-KDO are reported. The C2-symmetric dienediol 4 was desymmetrized by conversion to its corresponding 1,4-dioxanone 5. Ireland−Claisen rearrangement of 5 provided the 6-vinyldihydropyran-2-carboxylate template 6. Double-Sharpless asymmetric dihydroxylation gave the tetraol 7a, which was converted to KDO and 2-deoxy-β-KDO using methods similar to those previously reported. This synthetic scheme provides a flexible route to KDO and KDO analogues.