Second-Generation Synthesis of the Northern Fragment of Mandelalide A: Role of π-Stacking on Sharpless Dihydroxylation of <i>cis</i>-Enynes
作者:Ankan Ghosh、Alexander C. Brueckner、Paul Ha-Yeon Cheong、Rich G. Carter
DOI:10.1021/acs.joc.9b01153
日期:2019.7.19
asymmetric and diastereomeric dihydroxylation of cis-enynes is disclosed. The use of neighboring, electron-rich benzoate esters proved key to the success of this process. Density functional theory study suggests that the substrate benzoate ester group rigidifies the dihydroxylation transition states by forming a favorable π-stacking interaction in both Major-TS and Minor-TS. The energetic preference for
公开了一种基于π-堆叠的方法的发展,该方法用于增加顺式炔烃的Sharpless不对称和非对映异构二羟基化中的立体选择性。事实证明,使用相邻的富含电子的苯甲酸酯是该方法成功的关键。密度泛函理论研究表明,底物苯甲酸酯基团通过在Major-TS和Minor-TS中形成良好的π堆积相互作用,从而使二羟基化过渡态硬化。发现对Major-TS的能量偏爱部分是因为烯烃取代基具有良好的日蚀构象,而与Minor-TS中不利的二等分构象相反。证明了其在曼荼罗A的C15–C24北部的第二代合成中的应用。