A Novel Strategy for the Synthesis of Ammonium 3-Deoxy-D-manno-2-octulosonate (Ammonium KDO) from Lower Monosaccharides. C-C Bond Construction at C6 of D-Mannose via Cobaloxime-Mediated Radical Alkyl-Alkenyl Cross Coupling

Article abstract of DOI:10.1021/jo00267a017

Our synthesis of ammonium 3-deoxy-D-manno-2-octulosonate (ammonium KDO, 16) from D-mannose (3) proceeds in 10 one-flask operations in 1.5-1.6percent overall yield (66percent per operation).The strategic reaction is a C-C bond construction at C6 of D-mannose via photochemically induced radical cross coupling of α-ethoxyacrylonitrile with an alkyl cobaloxime derivative of D-mannose, in aqueous ethanol without protection of carbohydrate hydroxyls.In this paper we provide full experimental details of our KDO synthesis.In addition we provide some observations and insights on vanadium-catalyzed oxidations of α-hydroxy acids to α-keto acids.