Resolution of (±)-5-substituted-6-(5-chloropyridin-2-yl)-7-oxo-5,6-dihydropyrrolo[3,4b]pyrazine derivatives-precursors of (S)-(+)-Zopiclone, catalyzed by immobilized Candida antarctica B lipase in aqueous media
作者:Jose M Palomo、Cesar Mateo、Gloria Fernández-Lorente、Laura F Solares、Monica Diaz、Vı́ctor M Sánchez、Miguel Bayod、Vicente Gotor、Jose M Guisan、Roberto Fernandez-Lafuente
DOI:10.1016/s0957-4166(02)00867-4
日期:2003.2
The enzymatic resolution of different cyclopyrrolone compounds has been performed in aqueous systems using different immobilized preparations of lipase from Candida antarctica (fraction B). The relevance of the immobilizaition protocol in the results has been shown: lipase immobilized on octadecyl-Sepabeads gave the highest stability and enantioselectivity. Commercial Novozym 435 was scarcely enantioselective in the hydrolytic process. On the other hand, the structure of the cyclopyrrolone was also found to be very important to the outcome of the reaction, the best results being achieved with compounds (+/-)-l and (+/-)-2. Thus. using compound (+/-)-2. a ee(s) of < 95% can be achieved under conditions in which the enzyme preparation can be utilized in 10 recycles without any significant detriment to the enzymatic properties (activity, enantioselectivity). Moreover, this enzyme catalyzes the hydrolytic resolution of chloromethyl carbonate (+/-)-5, a useful intermediate for the synthesis of the hypnotic agent (S)-(+)-Zopiclone. (C) 2003 Elsevier Science Ltd. All rights reserved.