One enzyme convert (S)4-Chloro-3-hydroxybutyrate in the racemate to (S)-3-hydroxy-gamma-butyrolactone through asymmetric dechlorination, hydrolysis, and lactonization. Ethyl (S)-4-chloro-3-hydroxybutyrate is an intermediate for the synthesis of Atorvastatin, a chiral drug used for hypercholesterolemia