北京大学黎后华团队报道了Berkeleyone A 和 Preaustinoids的对映选择性全合成。相关研究成果发表在2021年4月15日出版的国际学术期刊《德国应用化学》。

该文报道了从市售的2,4,6-三羟基苯甲酸水合物出发，分12-15步首次对映选择性全合成3,5-二甲基或黄精酸衍生的meroterpenoids（）-berkeleyone A及其5个同系物（（）-preastinoids A，A1，B，B1和B2）。基于对D环内潜在对称性的认识，研究人员采用的聚合合成具有两个关键反应：（1）对称性破坏，非对映选择性脱芳烷基化以组装整个碳核，（2）Sc（OTf）3介导的顺序Krapcho脱甲氧基羰基化/羰基α-叔烷基化以锻造碳核复杂的双环[3.3.1]壬烷骨架。

研究人员还初步进行了仿生研究，并发现了一系列的重排（α-酮、α-羟基-β-二酮等）导致了Berkeleyone A的仿生多样化，变成了它的五种Preaustinoids同系物。

附：英文原文

Title: Enantioselective Total Synthesis of Berkeleyone A and Preaustinoids

Author: Houhua Li, Yang Zhang, Yunpeng Ji, Ivan Franzoni, Chuning Guo, Hongli Jia, Benke Hong

Issue&Volume: 2021-04-15

Abstract: Herein we report the first enantioselective total synthesis of 3,5‐dimethylorsellinic acid‐derived meroterpenoids ()‐berkeleyone A and its five congeners (()‐preaustinoids A, A1, B, B1 and B2) in 12‐15 steps, respectively, starting from commercially available 2,4,6‐trihydroxybenzoic acid hydrate. Based upon the recognition of latent symmetry within D‐ring, our convergent synthesis features two critical reactions: (1) a symmetry‐breaking, diastereoselective dearomative alkylation to assemble the entire carbon core, and (2) a Sc(OTf)  3  ‐mediated sequential Krapcho dealkoxycarbonylation/carbonyl α‐  tert  ‐alkylation to forge the intricate bicyclo[3.3.1]nonane framework. We also conducted our preliminary biomimetic investigations and uncovered a series of rearrangements (α‐ketol, α‐hydroxyl‐β‐diketone,  etc  ) responsible for the biomimetic diversification of ()‐berkeleyone A into its five preaustinoid congeners.

DOI: 10.1002/anie.202104014

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202104014