Gram-Scale Synthesis of ()Chlorophenyl-1,2-Ethanediol at High Concentration by a Pair of Epoxide Hydrolases.

()--chlorophenyl-1,2-ethanediol (CPED) is an important intermediate for the synthesis of ()-eliprodil that is widely applied in the treatment of ischemic stroke. To prepare ()-CPED with high enantiomeric excess ( ) and yield via the enantioconvergent hydrolysis of racemic styrene oxide (CSO) at high concentration, the bi-enzymatic catalysis was designed and investigated by a pair of epoxide hydrolases, a mutant (EH1) of EH1 and a mutant (EH) of EH Firstly, the maximum allowable concentration of -CSO was confirmed. Subsequently, the addition mode and the weight ratio of two cells were optimized. Finally, under the optimized reaction conditions-the cell weight ratio 20:1 of /1 to , a simultaneous addition mode, and reaction temperature at 25°C-300 mM CSO in the 100 ml 4% (v/v) Tween-20/phosphate buffer system (100 mM, pH 7.0) was completely hydrolyzed within 5 h, affording ()-CPED with 87.8% , 93.4% yield, and 8.63 g/L/h space-time yield (STY). This work would be an efficient technical strategy for the preparation of chiral vicinal diols at industrial scale.