Chemical synthesis of a comb-shaped, branched stereoregular polysaccharide, 4-O-alpha-D-mannopyranosyl-(1-->6)-alpha-D-mannopyranan.
4-O-alpha-D-Mannopyranosyl-(1-->6)-alpha-D-mannopyranan (7) was prepared via ring-opening polymerization of 1,6-anhydro-2,3-di-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-alpha-D- mannopyranosyl)-beta-D-mannopyranose (5) using phosphorus pentafluoride as initiator in dichloromethane at -60 degrees C, followed by debenzylation. Compound 5 was obtained via glycosidation of 1,6-anhydro-2,3-O- isopropylidene-beta-D-mannopyranose (1) with 2,3,4,6-tetra-O-benzyl-1-O-trichloroacetimidoyl-alpha-D-mannopyran ose (2) using p-toluenesulfonic acid as catalyst and subsequent transformation of the protecting groups of the resulting 1,6-anhydro-4-O-(2,3,4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-2,3- O-isopropylidene-beta-D-mannopyranose (3).
Faculty of Agriculture, Nagoya University, Japan.
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Kobayashi
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Nomura
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Okada
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000138:chemical synthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D009904:Optical Rotation
D004187:Disaccharides; D007202:Indicators and Reagents; D008351:Mannans; C081218:4-O-mannopyranosyl-(1-6)-mannopyranan