【摘 要】
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Amicetin and congeners constitute a small family of complex pyrimidine nucleosides,which exhibit strong antibiotic activities against Gram-positive bacteria and notably against strains of Mycobacterium tuberculosis.Herein,we report chemical synthesis of a
【机 构】
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State Key Laboratory of Bioorganic and Natural Products Chemistry,Center for Excellence in Molecular
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Amicetin and congeners constitute a small family of complex pyrimidine nucleosides,which exhibit strong antibiotic activities against Gram-positive bacteria and notably against strains of Mycobacterium tuberculosis.Herein,we report chemical synthesis of a series of disaccharide congeners of the amicetin family,including amicetin,plicacetin,and cytosaminomycin A-D.It is the first time for suc-cessful synthesis of amicetin,the prototypical member,and cytosaminomycins.The synthetic approach employs glycosyl N-phenyltrifluoroacetimidate and thioglycoside donors to construct the characteristic aminodeoxydisaccharides consisting of α-(1→4)-glycosidic linkage,uses gold(Ⅰ)-catalyzed N-glycosylation to furnish 2-deoxy-β-nucleosides,and finally exploits amidation and global deprotection to complete the syntheses.It is noteworthy that the 3-O-protecting group in the 2-deoxydisaccharide donors is found to be crucial for a successful N-glycosylation to assemble the cytosaminomycin disaccharide nucleosides.
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