Direct Synthesis of Glycans Containing Challenging ManNAcA Residues
Direct Synthesis of Glycans Containing Challenging ManNAcA Residues
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直接合成含有具有挑战性的 ManNAcA 残基的聚糖
DOI：
10.1021/acs.joc.1c02351
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Demchenko, Alexei V.
中科院分区：
文献类型：
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作者：
Alex, Catherine;Demchenko, Alexei V.
本文报道了一种直接、高立体选择性合成含有β-连接的甘露糖胺糖醛酸（ManNAcA）残基的聚糖的方法，其中包括金黄色葡萄球菌8型的荚膜多糖。这种聚糖的先前化学合成依赖于间接方法，包括葡糖基化，然后是多步差向异构化和氧化序列。使用H-键介导的糖苷配基递送（HAD）反应实现了3-O-吡啶甲酰化ManNAcA供体的直接糖苷化的高β-立体控制。还报道了用3-O-苯甲酰化供体实现完全α-ManNAcA立体选择性的方法。
A method for direct, highly stereoselective synthesis of glycans containing β-linkedd-mannosaminuronic acid (ManNAcA) residues is reported herein, among which is the capsular polysaccharide ofStaphylococcus aureustype 8. Previous chemical syntheses of this glycan relied on indirect methods comprising glucosylation followed by a multistep epimerization and oxidation sequence. The high β-stereocontrol with direct glycosidation of 3-O-picoloylated ManNAcA donors was achieved using the H-bond-mediated aglycone delivery (HAD) reaction. A method to achieve complete α-ManNAcA stereoselectivity with 3-O-benzoylated donors is also reported.