Development of a Phase Transfer Catalyzed Asymmetric Synthesis for an Estrogen Receptor Beta Selective Agonist
作者:Jeremy P. Scott、Michael S. Ashwood、Karel M. J. Brands、Sarah E. Brewer、Cameron J. Cowden、Ulf-H. Dolling、Khateeta M. Emerson、Andrew D. Gibb、Adrian Goodyear、Steven F. Oliver、Gavin W. Stewart、Debra J. Wallace
DOI:10.1021/op700178q
日期:2008.7.1
A practical asymmetric synthesis of the estrogen receptor beta selective agonist (7β-9aβ)-1,4-dichloro-2-hydroxygibba-1(10a),2,4,4b-tetraen-6-one (1), proceeding by way of six isolated intermediates and without recourse to chromatography, is described. Highlights of the process route developed are two chemoselective chlorinations, a lithiated hydrazone alkylation and an asymmetric Michael addition
实用的不对称合成雌激素受体β选择性激动剂(7β-9aβ)-1,4-dichloro-2-hydroxygibba-1(10a),2,4,4b-tetraen-6-one(1)进行描述了六种分离的中间体,无需借助色谱法。所开发工艺路线的重点是两次化学选择性氯化,锂化烷基化和在甲基乙烯基酮中使用茚满酮11的不对称迈克尔加成反应(使用15 mol%的辛可宁衍生催化剂20g)设置全碳四元不对称立体中心。详细讨论了将后者的异相双相转移反应规模扩展至44 mol(14 kg)规模时所面临的挑战。总体而言,开发的化学方法已用于制备> 6 kg候选药物1,总产率为18%,ee≥99%。