Studies on Catalytic Enantioselective Total Synthesis of Caprazamycin B: Construction of the Western Zone
作者:Purushothaman Gopinath、Takumi Watanabe、Masakatsu Shibasaki
DOI:10.1021/jo301803h
日期:2012.10.19
catalyst furnished the β-hydroxy thioamide in good yield and enantioselectivity. On further transformation, the thioamide functionality was converted to the corresponding β-hydroxy ester. Finally, a convergent synthesis of the western zone of caprazamycin B was achieved by connecting the hemiester, the β-hydroxy ester, and the 2,3,4-tri-O-methyl-l-rhamnose fragments.
我们描述了使用两个催化不对称反应作为我们方法的关键要素的一种简单便捷的卡普沙霉素B西部区域的合成方法。以(S)-Ni 2-(席夫碱)络合物为催化剂对3-甲基戊二酸酐进行不对称化反应,得到了手性半酯,以及与间苯二酚,(R,R)-Ph-BPE和2的硫酰胺-醛醇缩合反应, 2,5,7,8-五甲基苯并二氢苯并二氢苯并二氢吡喃醇作为催化剂以良好的产率和对映选择性提供了β-羟基硫代酰胺。进一步转化后,将硫酰胺官能团转化为相应的β-羟基酯。最后,通过连接半酯,β-羟基酯和2,3,4-tri-O-甲基-1-鼠李糖片段。