Enantioselective Synthesis of (−)-Terpestacin and (−)-Fusaproliferin: Clarification of Optical Rotational Measurements and Absolute Configurational Assignments Establishes a Homochiral Structural Series
作者:Andrew G. Myers、Michael Siu、Feng Ren
DOI:10.1021/ja020072l
日期:2002.4.1
An enantioselective synthesis of the syncytium formation inhibitor (-)-terpestacin (1, 19 steps, 5.8% yield from the allylation product of (R,R)-pseudoephedrine propionamide, 3) and the fungal metabolite (-)-fusaproliferin (2, 21 steps, 5.3% yield from 3) in their natural configurations is described. The route employs a series of stereoselective enolate alkylation reactions to establish the initial
合胞体形成抑制剂 (-)-terpestacin 的对映选择性合成(1, 19 个步骤,来自 (R, R)-伪麻黄碱丙酰胺的烯丙基化产物的产率为 5.8%,3)和真菌代谢物 (-)-fusaproliferin (2,描述了 21 个步骤,3) 在其自然配置中的产率为 5.3%。该路线采用一系列立体选择性烯醇烷基化反应来建立初始立体中心,设置季碳构型,关闭 15 元环,并通过适当的立体控制引入侧链残基。对我们的合成材料与天然样品的仔细分析表明,在早期的旋光度测量或这些天然产物的绝对立体化学分配中存在一些错误。澄清所有差异,我们在这里展示了天然萜烯 (1) 是左旋的,而不是最初描述的右旋,但被正确地指定为 (1S,11S,15R,23S)-对映异构体。据报道,Fusaproliferin (2) 是左旋的,但实际上是 (1S,11S,15R,23S)-对映异构体,而不是最初指定的对映体构型。