Total Syntheses of (−)-α-Kainic Acid and (+)-α-Allokainic Acid via Stereoselective C−H Insertion and Efficient 3,4-Stereocontrol
作者:Young Chun Jung、Cheol Hwan Yoon、Edward Turos、Kyung Soo Yoo、Kyung Woon Jung
DOI:10.1021/jo701988j
日期:2007.12.1
Reported herein is a novel approach to the total syntheses of (−)-α-kainic acid and (+)-α-allokainic acid, where the stereochemistries on C(2), C(3), and C(4) of the pyrrolidine core were introduced efficiently and selectively. A regio- and stereoselective C−H insertion reaction was utilized to prepare the γ-lactam as an intermediate. A Michael-type cyclization of phenylsulfone with a conjugated acetylenic
本文报道了一种全合成 (-)-α-红藻氨酸和 (+)-α-异海藻酸的新方法,其中 C(2)、C(3) 和 C(4) 的立体化学吡咯烷核心被有效和选择性地引入。利用区域选择性和立体选择性的 CH 插入反应来制备 γ-内酰胺作为中间体。开发了苯砜与共轭炔酮的迈克尔型环化,以制备三环酮作为 (-)-α-红藻氨酸的关键中间体。随后,成功地进行了立体选择性脱苯磺酰化,以确保 C(3) 和 C(4) 中心的顺式关系。苯砜上前所未有的乙酰化,然后是立体选择性脱苯磺酰化,确保了 (+)-α-allokainic 酸中 C(3) 和 C(4) 中心的反式关系。