Total Synthesis of the <i>Galbulimima</i> Alkaloids Himandravine and GB17 Using Biomimetic Diels–Alder Reactions of Double Diene Precursors
作者:Reed T. Larson、Ryan P. Pemberton、Jenna M. Franke、Dean J. Tantillo、Regan J. Thomson
DOI:10.1021/jacs.5b07710
日期:2015.9.2
enantioselective total syntheses of himandravine and GB17 were completed through a common biomimetic strategy involving Diels-Alder reactions of unusual double diene containing linear precursors. The double diene precursors, containing or lacking a C12 substituent as required to produce GB17 or himandravine, respectively, were found to undergo Diels-Alder reactions to afford mixtures of regioisomeric cycloadducts
Himandravine 和 GB17 的对映选择性全合成是通过一种常见的仿生策略完成的,该策略涉及不寻常的含有线性前体的双二烯的 Diels-Alder 反应。双二烯前体,分别含有或缺乏产生 GB17 或喜花树碱所需的 C12 取代基,经过 Diels-Alder 反应得到区域异构环加合物的混合物,映射到喜山树碱和 GB17 的替代碳环骨架上。计算研究表明,这些 Diels-Alder 反应通过具有高度双周特征的类似能量的过渡态结构进行,并且在反应中观察到的低水平区域选择性是竞争轨道相互作用和畸变能的结果。