Enzymatic esterification of an acid with an epoxide using an immobilized lipase from Mucor miehei as catalyst: optimization of the yield and isomeric excess of ester by statistical analysis.

We have developed the methodology for the esterification of an acid with an epoxide using 2-chlorobutyric acid and 1,2-epoxy-5-hexene catalysed by a Mucor miehei-immobilized lipase. Thus, this methodology could be applied to obtain 2-chloroesters. A factorial design of experiments and a central composite design have been used to optimise the synthesis of these esters. The variables chosen were temperature and initial catalyst concentration, while the responses were yield and isomeric excess of the ester. According to this study, temperature was the most important factor, having a positive influence on the yield and a small negative influence on the isomeric excess of the ester. The yield and isomeric excess of the ester show a greater dependence on temperature compared to the catalyst concentration. Although the effect of the catalyst concentration on both responses is smaller than the temperature effect, the higher selectivity presented by the biocatalyst towards the studied ester considerably decreased the final product distribution.