Department of Chemistry, Yale University, 225 Prospect Street, PO Box 20817, New Haven, CT, 06511, USA.
Angew Chem Int Ed Engl. 2019 Jan 21;58(4):1025-1029. doi: 10.1002/anie.201810566. Epub 2018 Dec 21.
A biomimetic cationic structural rearrangement of the oleanolic acid framework is reported for the gram-scale synthesis and structural reassignment of justicioside E aglycone. The mechanism of the putative biosynthetic rearrangement is investigated with kinetic, computational, and synthetic approaches. The precursor to rearrangement was accessed through two strategic advancements: (1) synthesis of a 1,3-diketone via oxidation of a β-silyl enone, and (2) diastereoselective 1,3-diketone reduction to form a syn-1,3-diol using SmI with PhSH as a key additive.
本文报道了齐墩果酸骨架的仿生阳离子结构重排，用于大规模合成和结构重分配苷元 jusiticoside E。通过动力学、计算和合成方法研究了假定的生物合成重排的机制。通过两种策略进展来获得重排前体：(1) 通过β-硅烯酮的氧化合成 1,3-二酮，和(2) 使用 SmI 并以 PhSH 作为关键添加剂进行立体选择性 1,3-二酮还原形成顺式-1,3-二醇。
