State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University , Tianjin 300071, P. R. China.
Innovative Drug Research Centre, Chongqing University , Chongqing 401331, P. R. China.
Org Lett. 2017 May 5;19(9):2250-2253. doi: 10.1021/acs.orglett.7b00743. Epub 2017 Apr 14.
We report a protocol for efficient stereoselective installation of the chiral oxygen-containing tetrasubstituted tertiary carbon stereocenter of the side chain of cephalotaxus esters by means of highly diastereoselective Mukaiyama aldol reactions between α-keto esters (2) and a (Z)-α-chloro ketene silyl acetal. This protocol permitted synthesis of cephalotaxus esters including six natural products in good to excellent yields (up to 94%) with high diastereoselectivities (dr up to 97:3) and could be performed on a multigram scale.
我们报告了一种通过高度非对映选择性 Mukaiyama 醛醇反应，在 α-酮酯（2）和（Z）-α-氯代烯酮硅基缩醛之间，在 cephalotaxus 酯的侧链中立体选择性地引入手性含氧四取代叔碳立体中心的有效立体选择性方案。该方案允许合成 cephalotaxus 酯，包括六个天然产物，产率高（高达 94%），非对映选择性好（dr 高达 97:3），并且可以进行多克规模的反应。
