State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, College of Chemistry, Collaborative Innovation Center of Chemical Science and Engineering , Nankai University , 94 Weijin Road , Tianjin 300071 , PR China.
Org Lett. 2018 May 4;20(9):2517-2521. doi: 10.1021/acs.orglett.8b00552. Epub 2018 Apr 17.
(-)-Englerin A was synthesized in 20 steps from the commercially available material ( R)-(+)-limonene. In addition, (-)-englerin B, (+)-orientalol E/F and (-)-oxyphyllol were obtained from the intermediate in the route. The key steps include a hydroxyl-directing stereoselective and regioselective intramolecular cyclopropanation and a multi-gram-scale stereoselective formal intramolecular [3 + 2] cross cycloaddition ([3 + 2]-IMCC) of a cyclopropane 1,1-diester with a carbonyl. A precursor of 7,10-diastereoisomer of englerins was also obtained.
(-)- 表马钱子碱 A 可由商业可得的材料 ( R)-(+)- 柠檬烯经 20 步合成。此外，还可从该路线的中间体中获得 (-)- 表马钱子碱 B、(+)- 东方醇 E/F 和 (-)- 氧化苦醇。关键步骤包括羟基导向的立体选择性和区域选择性分子内环丙烷化以及多克规模的立体选择性形式分子内 [3+2] 交叉环加成 ([3+2]-IMCC)，其中一个环丙烷 1,1- 二酯与羰基反应。还获得了马钱子碱 7,10- 非对映异构体的前体。
