Stereo- and enantioselectivity of the soluble epoxide hydrolase-catalysed hydrolysis of (±)-cis-dialkyl substituted oxiranes
作者:Cinzia Chiappe、Consiglia Doriana Palese
DOI:10.1016/s0040-4020(99)00657-2
日期:1999.9
into the corresponding threo-diols 2a-e by soluble epoxide hydrolase catalysed hydrolysis. The reaction proceeds with a substrate and product enantioselection, which is highly dependent on the substituents at the oxirane ring. Whereas the hydrolysis of racemic 1a shows practically no enantioselection, that of its isomer 1b, gives after complete hydrolysis, in a stereoconvergent way, the corresponding threo-diol
顺式-(±)-2,3-环氧庚烷(1a),顺式-3,4-环氧庚烷(1b),顺式-3,4-环氧壬烷(1c)顺式-3,4-环氧壬烷-1-醇的两种对映体(1d)和顺式-1-甲氧基-3,4-环氧壬烷(1e)通过可溶性环氧化物水解酶催化水解而转化为相应的苏-二醇2a-e。反应以底物和产物对映体进行,该对映体高度依赖于环氧乙烷环上的取代基。而外消旋体1a的水解几乎没有显示出其异构体1b的对映异构,完全水解后,以立体收敛的方式给出了相应的苏-二醇(3R,4R)-2b。另一方面,环氧化物1c-e的水解过程中,相当好的(1c和1e)或完全的(1d)底物对映体进行水解,得到外消旋体(2c)或以立体会聚的方式旋光富集(2e)或纯净的(2d)二醇。从以前用微粒体环氧化物水解酶水解相同底物的结果中观察到了显着差异。