INFLUENCES OF REACTION CONDITIONS ON THE ENANTIOSELECTIVE TRANSESTERIFICATION USING PSEUDOMONAS-CEPACIA LIPASE

The influences of different reaction conditions on Pseudomonas cepacia lipase (PCL) catalyzed esterification of several chiral allylic alcohols (2-(1-hydroxy-ethyl)acrylonitrile and some closely related compounds) have been investigated. These compounds are possible precursors in the synthesis of the antibiotic Nyccomycin. An increase in the reaction temperature led to an increased final conversion, decreased enantioselectivity of the reaction, and a reduction of the residual activity of the lipase. PCL is thermostable and catalytically active for more than 100 hours at 100-degrees-C. Variation of the chain length of the acyl group of the esters used as cosubstrates had only a small influence on the conversion. As expected, the alcohol generated during the synthesis had a strong negative influence on the progress of the reaction. PCL showed strong substrate selectivity for some of the tested allylic alcohols. The enantioselectivity changed from substrate to substrate.