Stereoselective β-Mannosylation by Neighboring-Group Participation
Stereoselective β-Mannosylation by Neighboring-Group Participation
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DOI：
10.1002/anie.201604358
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发表时间：
2016-09-05
影响因子：
16.6
通讯作者：
Boltje, Thomas J.
中科院分区：
文献类型：
--
作者：
Elferink, Hidde;Mensink, Rens A.;Boltje, Thomas J.
糖苷键的立体选择性合成是低聚糖合成的主要挑战。C2酰基取代基的邻基参与（NGP）可用于提供1,2-反式糖苷。近年来，随着C2手性助剂的出现，NGP的应用已扩展到1,2-顺式糖苷的制备。然而，这种方法被严格限制于1,2-顺式葡萄糖型糖的合成。本文报道了一种新型甘露糖基给体的设计和合成，该给体通过硫醚助剂的NGP提供1,2-顺式甘露糖苷。设计中的一个关键元素是使用C-1(4)锁定的甘露醛酸内酯来实现C2助剂的NGP。除了C2参与外，还发现了C4苄基远程参与的新模式，并提供了1,2-顺式甘露糖苷。
The stereoselective synthesis of glycosidic bonds is the main challenge of oligosaccharide synthesis. Neighboring-group participation (NGP) of C2 acyl substituents can be used to provide 1,2-trans-glycosides. Recently, the application of NGP has been extended to the preparation of 1,2-cis-glycosides with the advent of C2 chiral auxiliaries. However, this methodology has been strictly limited to the synthesis of 1,2-cis-gluco-type sugars. Reported herein is the design and synthesis of novel mannosyl donors which provide 1,2-cis-mannosides by NGP of thioether auxiliaries. A key element in the design is the use of C-1(4) locked mannuronic acid lactones to enable NGP of the C2 auxiliary. In addition to C2 participation a new mode of remote participation of the C4 benzyl group was identified and provides 1,2-cis-mannosides.