Dynamic Kinetic Resolution of 2,3-Dihydrobenzo[<i>b</i>]furans: Chemoenzymatic Synthesis of Analgesic Agent BRL 37959
作者:Patrick Bongen、Jörg Pietruszka、Robert Christian Simon
DOI:10.1002/chem.201200683
日期:2012.8.27
An efficient asymmetric synthesis of (S)‐2,3‐dihydrobenzo[b]furan‐3‐carboxylic acid (8 a) and (S)‐5‐chloro‐2,3‐dihydrobenzo[b]furan‐3‐carboxylic acid (8 b) was established. Key to the success was the highly stereoselective enzymatic kinetic resolution of the corresponding methyl or ethyl esters that was further developed into a dynamic process. As a reliable and fast tool for analysing the enantiomeric
(的有效不对称合成小号)-2,3-二氢苯并[ b ]呋喃-3-羧酸(8)和(小号)-5-氯-2,3-二氢苯并[ b ]呋喃-3-羧酸(8 b)成立。成功的关键是相应的甲酯或乙酯的高度立体选择性酶促动力学拆分,该拆分进一步发展成为一个动态过程。作为分析对映体过量的可靠且快速的工具,使用了带有CD检测器的HPLC。该路线是通过(S)-5-氯-2-3,2-二氢苯并[ b ]呋喃-3-羧酸乙酯的Friedel-Crafts酰化反应完成的(7 c),然后进行皂化,得到镇痛剂(S)-5-氯-2-3,3-二氢苯并[ b ]呋喃-3-羧酸(2)。