The present invention is to provide a process for simply producing an
optically active 3-hydroxypropionic ester derivative useful as a
medicament intermediate from an inexpensive material. More specifically,
the present invention is directed to a process for producing an optically
active 3-hydroxypropionic ester derivative comprising reacting an acetic
ester derivative available at low cost with a base and a formic ester,
thereby converting the acetic ester derivative into a 2-formylacetic
ester derivative, and thereafter, stereospecifically reducing the formyl
group of the derivative by use of an enzymatic source capable of
stereoselectively reducing the formyl group of the derivative.