Synthetic Studies Toward (−)-FR901483 Using a Conjugate Allylation To Install the C-1 Quaternary Carbon
作者:Dimitar B. Gotchev、Daniel L. Comins
DOI:10.1021/jo061677t
日期:2006.12.1
Both routes utilized a Grignard addition to an N-acylpyridinium salt to establish the absolute stereochemistry at C-6 and a highly diastereoselective conjugate allylation reaction to form the quaternary center at C-1 of the natural product in an excellent yield. Although the desired polysubstituted piperidine intermediates were prepared regio- and stereoselectively, the construction of the C-8/C-9
报告了(-)-FR901483的氮杂-三环十二烷骨架的两种方法。两种途径都利用了在N-酰基吡啶鎓盐中添加格氏试剂以建立C-6处的绝对立体化学,以及高度非对映选择性的共轭烯丙基化反应,从而以优异的产率在天然产物的C-1处形成了季铵盐中心。尽管期望的多取代的哌啶中间体是区域选择性和立体选择性地制备的,但仍不能实现C-8 / C-9键连接性的构建。频哪醇环化或分子内6-exo-tet环氧化物打开的所有尝试均未成功,因为分子中固有的不利的A (1,3)菌株。