Biomimetic Total Synthesis of (−)-Neroplofurol and (+)-Ekeberin D<sub>4</sub> Triggered by Hydrolysis of Terminal Epoxides
作者:Takeshi Kodama、Shingo Aoki、Tomoki Matsuo、Yoshimitsu Tachi、Keisuke Nishikawa、Yoshiki Morimoto
DOI:10.1246/cl.140618
日期:2014.10.5
To accumulate the chemical basis of epoxide-opening cascade biogenesis, chemical syntheses of sesqui- and triterpenoids were performed. The biomimetic total syntheses of (−)-neroplofurol (1) and (+)-ekeberin D4 (2) were accomplished by protic acid-catalyzed hydrolysis of the terminal epoxide from nerolidol diepoxide 3 and squalene tetraepoxide 4 through single and double 5-exo cyclizations in intermediates 5 and 6, respectively. This chemical reaction mimics the direct hydrolysis mechanism of epoxide hydrolases, enzymes that catalyze an epoxide-opening reaction to finally produce vicinal diols.
为了积累环氧开环级联生物合成的化学基础,进行了倍半萜和三萜的化学合成。(-)-neroplofurol (1) 和 (+)-ekeberin D4 (2) 的仿生全合成通过对nerolidol diepoxide 3 和squalene tetraepoxide 4中末端环氧化物的质子酸催化水解,分别通过中间体5和6的单重和双重5-exo环化反应完成。这个化学反应模拟了环氧水解酶的直接水解机制,这些酶催化环氧开环反应,最终生成邻二醇。