Template-directed intramolecular C-glycosidation. Total synthesis of 2,3-dideoxy-d-manno-2-octulopyranosonic acid

Abstract The total synthesis of the KDO-inhibitor 2,3- dideoxy- d -manno-2- octulopyranosonic acid (2-deoxy-KDO) starting from TBDPS-protected ( S )-glycidol and 3,3-dimethoxy-1-(phenylsulfonyl)-propane is described. The key steps are silver(I) trifluoromethylsulfonate-mediated cyclisation of the cinnamyl ether 6 , and Na(Hg)-induced reductive ring-opening of the bicyclic alcohol 15 .