PURPOSE: To obtain the titled substance in high conversion ratio and in high optical yield, by asymmetrically reducing an olefin derivative such as 2-phenyl-3- methylcrotonic acid, etc., with hydrogen in the presence of a metallic catalyst modified with an optically active binaphthyl derivative.

CONSTITUTION: An olefin derivative shown by formula I (R1 and R2 are H or lower alkyl; R3 and R4 are H, halogen, lower alkyl or lower alkoxyl) is asymmetrically reduced with hydrogen in the presence of a metallic catalyst modified with an optically active binaphthyl derivative to give compound shown by formula II. A transition metal such as Rh, Ir, Ru, etc., is preferable as the metallic component of the catalyst and a phosphine derivative shown by formula III (R is phenyl, p-tosyl, cyclohexyl, etc.) is preferable as the optical active binaphthyl derivative of a modifying agent. The reaction is usually carried out in a solvent such as methanol at 50W100°C for 1W20hr. Used as an intermediate for drugs and agricultural chemicals.