Divergent total synthesis of the revised structures of marine anti-cancer meroterpenoids (+)-dysiherbols A–E
Chuanke Chong, Le Chang, Isabelle Grimm, Qunlong Zhang, Yang Kuang, Bingjian Wang, Jingyi Kang, Wenhui Liu, Julian Baars, Yuanqiang Guo, Hans‐Günther Schmalz, Zhaoyong Lu
Abstract
direct cyclization, while (+)-dysiherbol E (10) was synthesized through allylic oxidation and subsequent cyclization of 14. Epoxidation of 14 afforded allylic alcohol 45 or unexpectedly rearranged homoallylic alcohol 44. By inverting the configuration of the hydroxy groups, exploiting a reversible 1,2-methyl shift and selectively trapping one of the intermediate carbenium ions through oxy-cyclization, we succeeded to complete the total synthesis of (+)-dysiherbols B-D (7-9). The total synthesis of (+)-dysiherbols A-E (6-10) was accomplished in a divergent manner starting from dimethyl predysiherbol 14, which led to the revision of their originally proposed structures.