Complex Polypropionates from a South China Sea Photosynthetic Mollusk: Isolation and Biomimetic Synthesis Highlighting Novel Rearrangements
Complex Polypropionates from a South China Sea Photosynthetic Mollusk: Isolation and Biomimetic Synthesis Highlighting Novel Rearrangements
复制标题
来自南海光合软体动物的复杂聚丙酸盐：分离和仿生合成突出新的重排
DOI：
10.1002/anie.202003643
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发表时间：
2020-05-20
影响因子：
16.6
通讯作者：
Li, Xu-Wen
中科院分区：
文献类型：
--
作者：
Wu, Qihao;Li, Song-Wei;Li, Xu-Wen
众所周知，Placobranchus ocellatus可以生产多种复杂的γ -吡咯酮聚丙酸酯。在本研究中，对来自南海的P. ocellatus进行了化学调查，发现并鉴定了ocellatusones a- d，这是一系列具有新骨架的外消旋非γ -吡咯酮聚酮，其特征为双环[3.2.1]辛烷（1,2），双环[3.3.1]壬烷(3)或甲亚甲基取代的二甲基呋喃-3(2H)-一核(4)。通过广泛的光谱分析、量子化学计算、化学合成和/或x射线衍射分析来确定新化合物的结构和绝对构型，包括手性HPLC解析后的外消旋化合物1-4的每个对映体。基于仔细的结构分析和与六种已知共发生的γ -吡咯酮的比较，提出了一系列新的和产生多样性的重排来解释这些不寻常化合物的生物合成（5-10）。此外，成功的仿生半合成ocellatusone A(1)通过前所未有的酸诱导级联反应证实了所提出的重排。
Placobranchus ocellatus is well known to produce diverse and complex gamma-pyrone polypropionates. In this study, the chemical investigation of P. ocellatus from the South China Sea led to the discovery and identification of ocellatusones A-D, a series of racemic non-gamma-pyrone polyketides with novel skeletons, characterized by a bicyclo[3.2.1]octane (1, 2), a bicyclo[3.3.1]nonane (3) or a mesitylene-substituted dimethylfuran-3(2H)-one core (4). Extensive spectroscopic analysis, quantum chemical computation, chemical synthesis, and/or X-ray diffraction analysis were used to determine the structure and absolute configuration of the new compounds, including each enantiomer of racemic compounds 1-4 after chiral HPLC resolution. An array of new and diversity-generating rearrangements is proposed to explain the biosynthesis of these unusual compounds based on careful structural analysis and comparison with six known co-occurring gamma-pyrones (5-10). Furthermore, the successful biomimetic semisynthesis of ocellatusone A (1) confirmed the proposed rearrangement through an unprecedented acid induced cascade reaction.