Syntheses of (+)-30-<i>epi</i>-, (−)-6-<i>epi</i>-, (±)-6,30-<i>epi</i>-13,14-Didehydroxyisogarcinol and (±)-6,30-<i>epi</i>-Garcimultiflorone A Utilizing Highly Diastereoselective, Lewis Acid-Controlled Cyclizations
作者:Jonathan H. Boyce、Vincent Eschenbrenner-Lux、John A. Porco
DOI:10.1021/jacs.6b09727
日期:2016.11.9
The first syntheses of 13,14-didehydroxyisogarcinol (6) and garcimultiflorone A (5) stereoisomers are reported in six steps from a commercially available phloroglucinol. Lewis acid-controlled, diastereoselective cationic oxycyclizations enabled asymmetric syntheses of (-)-6-epi-6 and (+)-30-epi-6. A similar strategy enabled production of the meso-dervied isomers (±)-6,30-epi-6 and (±)-6,30-epi-5. Finally
据报道,从市售间苯三酚分六个步骤首次合成了 13,14-二脱羟基异藤黄酚 (6) 和 garcimultiflorone A (5) 立体异构体。路易斯酸控制的非对映选择性阳离子氧环化能够实现 (-)-6-epi-6 和 (+)-30-epi-6 的不对称合成。类似的策略能够生产内消旋衍生异构体 (±)-6,30-epi-6 和 (±)-6,30-epi-5。最后,开发了一种方便的克级合成策略,利用合成后期的非对映异构体分离,最大限度地减少了获得所有可能的立体异构体所需的合成操作数量。