Synthesis of (+)-calanolide A, an anti-HIV agent, Via enzyme-catalyzed resolution of the aldol products
作者:Albert Khilevich、Aye Mar、Michael T. Flavin、John D. Rizzo、Lin Lin、Sergey Dzekhtser、Darko Brankovic、Heping Zhang、Wei Chen、Shuyuan Liao、David E. Zembower、Ze-Qi Xu
DOI:10.1016/0957-4166(96)00433-8
日期:1996.11
The synthesis of (+)-calanolide A (1), an anti-HIV-1 agent, is described. A TiCl4-mediated aldol reaction of compound 2 stereoselectively produced the desired syn diastereomer (+/-)-5, which was resolved by a lipase-catalyzed acylation reaction. Under Mitsunobu conditions (Ph(3)P/DEAD), the syn aldol product (+)-5 led to the formation of trans-2,3-dimethyl chroman-4-one [(+)-3] with 94% ee, while the anti aldol product (+)-6 yielded both trans and cis derivatives (+)-3 and (+)-4 with 60% and 68% ee, respectively. Luche reduction on (+)-3 led to (+)-1 and (+)-calanolide B in a ratio of 9 : 1. Copyright (C) 1996 Elsevier Science Ltd