CARB 31 |
| The principal challenge in synthesis of complex oligosaccharide of biological importance is the development of a general methodology for the stereoselective introduction of 1,2-cis-á-glycosidic linkage. A novel glycosyl donor was designed rationally and prepared to perform new neighboring group participation for 1,2-cis-á-glycoside. It is shown that a (S)-(phenylthiomethyl)benzyl moiety at C-2 of a glycosyl donor can perform neighboring group participation to give a stable cyclic sulfonium ion. Due to steric and electronic factors, the sulfonium ion is formed as a trans-decalin ring system. Displacement of the sulfonium ion by a hydroxyl leads to the stereoselective formation of á-glycoside. The use of the new methodology in combination with traditional neighboring group participation to introduce â-glycoside make it possible to synthesize a wide variety of complex oligosaccharides by routine procedures. |
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General Posters
6:00 PM-8:00 PM, Tuesday, 28 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Carbohydrate Chemistry |