Separation Science and Technology, Vol.34, No.13, 2663-2678, 1999
Selection of pure enantiomers of 1-phenyl alcohols by sequenced processes of ester hydrolysis and transesterification in enzyme membrane reactors
Research aimed on selecting the particular enantiomers in sequenced processes is described. The work presents experimental results on performing hydrolysis of 1-phenyl alcohol ester and transesterifications in the system vinyl acetate and 1-phenyl alcohols in batch and in membrane reactors. Lipase from Pseudomonas sp. has been used as the biocatalyst for both processes. This catalyst exhibits high catalytic activity and the same enantioselectivity when used in solution (batch reactor) and when immobilized within polyamide membranes (membrane reactor). Using the mixture of products from the hydrolysis of 1-phenylethyl propionate, which can exhibit a moderate or low enantiomeric purity, to the next process of transesterification with vinyl acetate leads to products of high enantiomeric purity (enantiomeric excess > 97%). This procedure could be a good way to produce substances with the pure enantiomeric block needed for further syntheses of enantiomerically pure compounds. It is convenient to perform the processes in reactors with lipase chemically immobilized within the polyamide membranes.