Total Synthesis of (+)-Xestoquinone Using an Asymmetric Palladium-Catalyzed Polyene Cyclization
作者:Shawn P. Maddaford、Neil G. Andersen、Walter A. Cristofoli、Brian A. Keay
DOI:10.1021/ja960807k
日期:1996.1.1
The first total asymmetric synthesis of (+)-xestoquinone (1) has been accomplished in 68% ee by a palladium(0)-catalyzed polyene cyclization of naphthyl triflate 44 using (S)-(+)-BINAP as the chiral ligand. Attempts at an asymmetric polyene cyclization using the corresponding naphthyl bromide 41 gave poor enantioselectivities even in the presence of silver salts, thus exemplifying the effect of the
使用 (S)-(+)-BINAP 作为手性配体,通过钯 (0) 催化的三氟甲磺酸萘酯 44 的多烯环化反应以 68% ee 完成了 (+)-xestoquinone (1) 的首次全不对称合成。即使在银盐存在的情况下,使用相应的萘基溴 41 进行不对称多烯环化的尝试也给出了较差的对映选择性,因此举例说明了钯的配位状态对对映选择性的影响。还描述了一种在七元环醚前体上使用 [1,2]-Wittig 重排制备 6,7-二氢异苯并呋喃的新方法。