Stereospecific enzymatic hydrolysis of racemic epoxide: a process for making chiral epoxide
作者:Animesh Goswami、Michael J. Totleben、Ambarish K. Singh、Ramesh N. Patel
DOI:10.1016/s0957-4166(99)00326-2
日期:1999.8
Among various microbial cultures evaluated, Rhodotorula glutinis SC 16293 and Aspergillus niger SC 16311 catalyzed the stereospecific hydrolysis of the racemic epoxide, RS-1-2',3'-dihydrobenzo[b]furan-4'-yl}-1,2-oxirane, 1 to the corresponding R-diol, R-1-2',3'-dihydrobenzo[b]furan-4'-yl}-ethane-1,2-diol, 3. The S-epoxide, S-1-2',3'-dihydrobenzo[b]furan-4'-yl}-1,2 remained unreacted in the reaction mixture. A reaction yield of 45-50% (theoretical maximum yield is 50%) and an enantiomeric excess (ee) of >95% were obtained for unreacted S-epoxide 2 using each culture. Addition of 10% methyl tert-butyl ether to an aqueous reaction mixture during hydrolysis by R. glutinis improved the ee of the unreacted S-epoxide 2 to >99% (yield 48%) and that of the R-diol 3 to 79%. Unlike R. glutinis, hydrolysis of racemic epoxide 1 in the presence of 10% methyl tert-butyl ether by A. niger showed an adverse effect and gave S-epoxide 2 in 54% yield and 49% ee. (C) 1999 Elsevier Science Ltd. All rights reserved.