(−)‐Isoscopariusin A, a Naturally Occurring Immunosuppressive Meroditerpenoid: Structure Elucidation and Scalable Chemical Synthesis
作者:Bing‐Chao Yan、Min Zhou、Jian Li、Xiao‐Nian Li、Shi‐Jun He、Jian‐Ping Zuo、Han‐Dong Sun、Ang Li、Pema‐Tenzin Puno
DOI:10.1002/anie.202100288
日期:2021.6
(−)-Isoscopariusin A was isolated from the aerial parts of Isodon scoparius. Chemical synthesis and spectroscopic analysis established its structure as an unsymmetrical meroditerpenoid bearing a sterically congested 6/6/4 tricyclic carbon skeleton with seven continuous stereocenters. A gram-scale synthesis was achieved in 12 steps from commercially available (+)-sclareolide. A cobalt catalyzed, hydrogen atom transfer-based
(-)-Isoscopariusin A 从Isodon scoparius地上部分分离. 化学合成和光谱分析确定其结构为不对称的亚二萜,具有空间拥挤的 6/6/4 三环碳骨架,具有七个连续立体中心。从市售的 (+)-紫苏内酯分 12 个步骤实现了克级合成。钴催化的基于氢原子转移的烯烃异构化用于制备三取代的烯烃,该烯烃与由相应酰胺原位生成的取代的烯酮亚胺离子进行立体选择性[2+2]环加成。通过面选择性同系化将环丁酮产物进一步加工成完全取代的环丁烷核,并通过镍催化的交叉亲电偶联和碳二亚胺介导的酯化分别安装两条侧链。