Synthesis of methyl pyranosides and furanosides of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) by acid-catalysed solvolysis of the acetylated derivatives.
Treatment of methyl 2,4,5,7,8-penta-O-acetyl-3-deoxy-alpha-D-manno-oct- 2-ulopyranosonic acid, or its methyl ester, with refluxing methanolic 0.1 M hydrogen chloride for 16 h gave 95% of methyl (methyl 3-deoxy-alpha-D-manno-oct-2-ulopyranosid)onate. Acetylation of the methyl ester of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) gave mainly methyl 2,4,6,7,8-penta-O-acetyl-3-deoxy-alpha,beta-D-manno-oct-2-ulofuranoso nate. Treatment of this mixture with methanolic 0.02 M hydrogen chloride at room temperature gave methyl (methyl 3-deoxy-alpha, beta-D-manno-oct-2-ulofuranosid)onate and the corresponding 4-acetates which were isolated by reverse-phase column chromatography of their 7,8-O-isopropylidene derivatives. Confirmation of the position of the isopropylidene group was obtained by acetylation to give methyl (methyl 4,6-di-O-acetyl-3-deoxy-7,8-O-isopropylidene-alpha,beta-D-manno-oct-2-ul ofuranosid)onate. The furanose anomers were differentiated primarily by J3,4 values (alpha approximately 6.1 Hz, beta approximately 2.2 Hz). The anomeric configuration in the furanose series has been assigned on the basis of optical rotation.
McNicholas
P A
PA
Batley
M
M
Redmond
J W
JW
D001886:Bordetella pertussis / Q000276:immunology; D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D006027:Glycosides / Q000138:chemical synthesis; D007202:Indicators and Reagents; D008070:Lipopolysaccharides; D009682:Magnetic Resonance Spectroscopy; D008759:Methylglycosides / Q000138:chemical synthesis; D009904:Optical Rotation; D013329:Structure-Activity Relationship; D013400:Sugar Acids / Q000138:chemical synthesis*
D006027:Glycosides; D007202:Indicators and Reagents; D008070:Lipopolysaccharides; D008759:Methylglycosides; D013400:Sugar Acids; C002532:2-keto-3-deoxyoctonate