Rapid Transformation of <scp>d</scp>-Mannose into Orthogonally Protected <scp>d</scp>-Glucosamine and <scp>d</scp>-Galactosamine Thioglycosides
作者:Madhu Emmadi、Suvarn S. Kulkarni
DOI:10.1021/jo200342v
日期:2011.6.3
An expedient protocol for synthesis of orthogonally protected 2-azido-2-deoxy-d-glucosamine and 2-azido-2-deoxy-d-galactosamine donors from d-mannose is described. Readily available phenyl β-d-thiomannoside is rapidly transformed into d-GlcN3 thioglycosides via a highly regioselective 3-O-acylation followed by 4,6-O-benzylidenation and azide displacement of C2-OTf, which is further converted into d-GalN3
对于正交保护的合成一种适宜协议2-叠氮基-2-脱氧d -葡糖胺和2-叠氮基-2-脱氧d从-galactosamine献血者d甘露糖进行说明。容易获得的苯基β- d -thiomannoside被迅速转化为d -GlcN 3硫代糖苷经高度选择性3- ö酰化,随后4,6- Ó -benzylidenation和叠氮化位移C2-光学传递函数,其被进一步转换成d - GalN 3通过C4羟基的Lattrell-Dax转化及其硫代糖苷保护获得硫糖苷。反应序列可以在2天之内完成,并且涉及简单的后处理和最少的柱色谱法。