Asymmetric acetylations of prochiral diols 3a-d with isopropenyl acetate were investigated with different commercial and self prepared lipases. Continuous flow mode reactions were performed in small stainless steel packed-bed reactors which can precisely control temperature (-10-200 degrees C), pressure (0-150 bar) and flow rate (0.1-3.0 mL/min). The effect of the temperature and flow-rate on the conversion and enantiomer excess of the chiral monoesters was investigated.