Department of Synthetic Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
Angew Chem Int Ed Engl. 2021 Nov 8;60(46):24484-24487. doi: 10.1002/anie.202110556. Epub 2021 Oct 11.
Herein, we describe the first total synthesis of cochlearol B, a meroterpenoid natural product featuring a 4/5/6/6/6-fused pentacyclic structure. Key steps, oxidative cyclization and subsequent intramolecular [2+2] photocycloaddition, which constructed the pentacyclic structure in highly stereoselective manner, allowed efficient access to cochlearol B with the longest linear sequence of 16 steps, and in 9 % overall yield. Single-crystal X-ray crystallographic analysis clearly confirmed the stereochemistry of cochlearol B.
本文描述了 Cochlearol B 的首次全合成，这是一种具有 4/5/6/6/6 稠合五环结构的倍半萜类天然产物。关键步骤包括氧化环化和随后的分子内[2+2]光环加成，这些步骤以高度立体选择性的方式构建了五环结构，从而以最长的 16 步线性序列和 9%的总收率高效地获得 Cochlearol B。单晶 X 射线晶体学分析清楚地证实了 Cochlearol B 的立体化学。
