New Route to 3-Deoxy-2-Ulosonic Acids; Total Syntheses of KDO and KDN

✍ Scribed by Hirokazu Tsukamoto; Takashi Takahashi

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 591 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)01484-6

✦ Synopsis

Syntheses of KDO and KDN by alkylation of 2-alkoxy-2-cyanoacetate anion, an acyl anion equivalent of alkyl glyoxylate, with a sugar-derived iodide and triflate are described.@ 1997 Elsevier Science Ltd.

3-Deoxy-D-manno-2-octulosonic acid (KDO; 1)1)and 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN; 6)2) possess a common synthetically challenging structure characterized by the presence of pyruvic acid moiety. KDO is found in the lipopolysaccharide segion of the cell surface of all Gram-negative bacteria and is an essentiaI component for their replication. KDN occurs in the nonreducing termini in polysialoglycoproteins (PSGP) and protects oligopolysialyl chains from exosialidme. These important findings have stimulated significant effort toward the syntheses of various 3-deoxy-2-ulosonic acid derivatives.3) One of the problems in the syntheses of such molecules is the introduction of the tz-ketoacid system. Among the reported enzymatic