A Non-Aldol Preparation of Enantiopure Propionate-Derived Motifs with the Assistance of Chiral Sulfoxides: Application to a Convergent Synthesis of the Lactone Core of Octalactins
作者:Claude Bauder
DOI:10.1002/ejoc.201500527
日期:2015.8
anti configuration. As an application of this work, we have described an enantioselective synthesis of the unusual eight-membered lactone ring of the octalactins. Two propionate-derived fragments were coupled to give precursor 18, which was subjected to Yamaguchi's macrolactonisation to give the required lactone ring.
使用手性亚砜化学通过非羟醛方法制备丙酸酯衍生的片段。在手性亚砜作为助剂的辅助下,甲基丙烯酸酯很容易转化为光学纯的烯丙醇,然后与庞大的二烷基硼烷 9-BBN 进行非对映选择性硼氢化反应。考虑到各种 A(1,2) 烯丙基菌株,正如 Houk 所建议的那样,非对映面选择性受交错构象模型的首选空间排列控制。因此,对映纯烯丙醇中的两个相邻立体中心以反构型安装。作为这项工作的应用,我们描述了八内酯的不寻常的八元内酯环的对映选择性合成。两个丙酸盐衍生的片段偶联得到前体 18,