Stereospecific synthesis of 1,2-cis glycosides by allyl-mediated intramolecular aglycon delivery.: 2.: The use of glycosyl fluorides
Stereospecific synthesis of 1,2-cis glycosides by allyl-mediated intramolecular aglycon delivery.: 2.: The use of glycosyl fluorides
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DOI：
10.1021/ol016175a
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发表时间：
2001-07-26
期刊：
影响因子：
5.2
通讯作者：
Redgrave, AJ
中科院分区：
文献类型：
--
作者：
Cumpstey, I;Fairbanks, AJ;Redgrave, AJ
报道了2-O-烯丙基保护的葡萄糖基和甘露糖基氟化物通过烯丙基异构化、N-碘代琥珀酰亚胺介导的束缚和分子内糖苷配基递送（IAD）的序列的立体特异性1，2-顺式糖基化。使用氟化物作为异头离去基团是有利的，因为可以通过使用延长的反应时间而没有竞争性异头活化来增加受阻糖苷配基醇的束缚效率，分子内糖基化以完全立体选择性的方式取代所需的α-葡糖苷和β-甘露糖苷。
[GRAPHICS]Stereospecific 1,2-cis glycosylation of 2-O-allyl-protected glucosyl and mannosyl fluorides via a sequence of allyl isomerization, N-iodosuccinimide-mediated tethering, and intramolecular aglycon delivery (IAD) is reported, The use of fluoride as anomeric leaving group is advantageous in that tethering efficiencies can be increased for hindered aglycon alcohols by the use of extended reaction times without competitive anomeric activation, Intramolecular glycosylation furnishes the desired alpha -glucosides and beta -mannosides in an entirely stereoselective manner.