Facile and Effective Synthesis of Glucopyranosyl Oligosacchardes with Alternative (1→3)-α- and -β-Li

来源 :Chinese Journal of Chemistry | 被引量 : 0次 | 上传用户:piaoye2008
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Coupling of acetylated α-(1→3)-linked glucobiosyl trichloro-acetimidate with acetylated α-(1→3)-linked glucobioside acceptor gave a β-linked tetrasaccharide, while coupling of acetylated β-(1→3)-linked glucobiosyl trichloroacetimidate with acetylated β-(1→3)-linked glucobioside acceptor gave an α-linked tetrasaccharide in spite of the C-2 neighboring group participation. Two hexasaccharides with alternative (1→3)-α- and -β-linkges were synthesized by these reactions via remote control exerted by the glycosylation bond in either donor or acceptor. Coupling of acetylated α- (1 → 3) -linked glucobiosyl trichloro-acetimidate with acetylated α- (1 → 3) -linked glucobioside acceptor gave a β-linked tetrasaccharide, while coupling of acetylated β- (1 → 3) -linked glucobiosyl trichloroacetimidate with acetylated β- (1 → 3) -linked glucobioside acceptor gave an α-linked tetrasaccharide in spite of the C-2 neighboring group participation. Two hexasaccharides with alternative (1 → 3) -α- and -β-linkages were also synthesized. by these reactions via remote control exerted by the glycosylation bond in either donor or acceptor.
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