Enzymatic synthesis of n-octyl (+)-2-methylbutanoate ester from racemic (±)-2-methylbutanoic acid by immobilized lipase: optimization by statistical analysis

An enantioselective esterification process was developed for the direct synthesis of n-octyl (+)-2-methylbutanoate ester from racemic (±)-methylbutanoaic acid by using n-octanol and Candida antarctica immobilized lipase as the biocatalyst in a batch reactor. A Factorial Design of Experiments and a Central Composite Design have been used in the synthesis of this fine chemical. The variables chosen were temperature and initial catalyst concentration. Response surface models were applied to represent the yield of ester and the enantiomeric excess of the remaining acid.