Hou Si-Hua, Tu Yong-Qiang, Wang Shuang-Hu, Xi Chao-Chao, Zhang Fu-Min, Wang Shao-Hua, Li Yan-Tao, Liu Lin
State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P.R. China.
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P.R. China.
Angew Chem Int Ed Engl. 2016 Mar 24;55(14):4456-60. doi: 10.1002/anie.201600529. Epub 2016 Mar 3.
Total syntheses of the biologically important and structurally unique tetracyclic diterpenes conidiogenone, conidiogenol, and conidiogenone B of the cyclopiane class are reported. The absolute configuration of naturally occurring conidiogenone B was also corrected. The key step of our strategy involved the highly efficient construction of both ring C and the quaternary carbon center shared by rings A and C through a one-step regioselective and diastereoselective cycloenlargement in the form of a semipinacol-type rearrangement. In particular, the desired regioselectivity was made possible by properly adjusting the migratory aptitude of the migrating carbon atom through the introduction of an electron-donating phenylthio group at this position.
报道了具有生物学重要性且结构独特的环戊烷类四环二萜类化合物分生孢子源酮、分生孢子源醇和分生孢子源酮B的全合成。还修正了天然存在的分生孢子源酮B的绝对构型。我们策略的关键步骤包括通过半频哪醇型重排的一步区域选择性和非对映选择性环扩大反应，高效构建环C以及环A和环C共有的季碳中心。特别地，通过在该位置引入供电子的苯硫基来适当调节迁移碳原子的迁移能力，从而实现了所需的区域选择性。
