Stereospeci®c synthesis of -C-glycosyl derivatives (`` -C-glycosides'') of N-acetylneuraminic acid by samarium-mediated reductive desulfonylation of a glycosyl phenylsulfone
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چکیده
A samarium-mediated Barbier reaction was performed to aord N-acetylneuraminic acid -Cglycosyl compounds (`` -C-glycosides'') in excellent yield. The neuraminic acid phenyl sulfone or 2-pyridyl sulfone derivatives reacted with ketones or aldehydes resulting in the instantaneous and stereospeci®c formation of Neu5Ac -C-glycosides. The phenyl and the 2-pyridyl sulfone derivatives were equally eective in this reaction. Finally, this procedure was successfully applied to the preparation of C-disaccharide, -Neu5Ac-(2!6) Gal. # 1998 Elsevier Science Ltd. All rights
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