Enzymatic resolution of ethyl 3-hydroxy-3-phenylpropanoate and analogs using hydrolases

This work contributes to the substrate model study of enzymatic hydrolysis of secondary and tertiary beta -hydroxy esters. One secondary and four tert iary beta -hydroxy esters have been employed with PCL, PLE, CRL and AOP enz ymes. The best result was observed when PCL was used as an enzyme for the r eaction of the secondary ester, ethyl 3-hydroxy-3-phenylpropanoate (1a) (co nversion of 50%, ester (R)-1a recovered with 98% e.e. and the acid 1 with 9 3% e.e. On the other hand, PLE showed the best result for tertiary ethyl 3- hydroxy-3-phenylbutanoate (2a) and ethyl 3-cyclohexyl-3-hydroxy-3-phenylpro panoate (3a), despite the poor selectivity. Ethyl 2-(1-hydroxycyclohexyl)-b utanoate (4a) and ethyl 2-(1-hydroxycyclopentyl)-butanoate (5a) were only h ydrolyzed by PLE and CRL, but showed no enantioselectivity.