Synthesis of enantiopure planar chiral bis-(<i>para</i>
)-pseudo-<i>meta</i>
-type [2.2]paracyclophanes
作者:Risa Sawada、Masayuki Gon、Jun Nakamura、Yasuhiro Morisaki、Yoshiki Chujo
DOI:10.1002/chir.23010
日期:2018.10
A new type of planar chiral (Rp)‐ and (Sp)‐4,7,12,15‐tetrasubstituted [2.2]paracyclophanes was prepared from racemic 4,7,12,15‐tetrabromo[2.2]paracyclophane as the starting substrate. Regioselective lithiation and transformations afforded racemic bis‐(para)‐pseudo‐meta‐type [2.2]paracyclophane (4,15‐dibromo‐7,12‐dihydroxy[2.2]paracyclophane). Its optical resolution was performed by the diastereomer
以外消旋的4,7,12,15-四溴[2.2]对环糊精为原料制备了一种新型的平面手性(R p)-和(S p)-4,7,12,15-四取代[2.2]对环环烷基质。区域选择性锂化和得到外消旋双(转换段)-pseudo-元型[2.2]对环芳烷(4,15二溴-7,12-二羟基[2.2]二聚二甲苯)。其光学拆分通过非对映异构体方法使用手性樟脑酰基作为手性助剂来进行。非对映异构体很容易通过简单的硅胶柱色谱分离,并通过连续水解得到(R p)-和(S p)-bis-(对位)-伪-元型[2.2]对环环糊精((R p)-和(S p)-4,15-二溴-7,12-二羟基[2.2]对环环糊精)。它们可以用作伪元取代的手性构件。