Patent ID: 7649117

Claim:
A process of preparing an optically active-hydroxycarboxylic acid derivative represented by formula (III): wherein R 1 represents an aryl group, a substituted aryl group or a substituted alkyl group in which at least one hydrogen atom of an alkyl group is displaced with a halogen atom; R 2 and R 3 , which may be the same or different, each represent a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, a substituted aralkyl group, an aryl group, a substituted aryl group, an aliphatic heterocyclic group, a substituted aliphatic heterocyclic group, an aromatic heterocyclic group, or a substituted aromatic heterocyclic group; R 4 has the same meaning as R 1 , R 2 , or R 3 or represents a group comprising an oxygen atom and the group which is represented by R 1 , R 2 , or R 3 and is bonded to the oxygen atom, or represents an amino group or a substituted amino group; and the asterisk * indicates an asymmetric center, comprising asymmetrically hydrogenating a β-keto compound represented by formula (I): wherein R 1 , R 2 , R 3 , and R 4 are as defined above, in the presence of a catalyst comprising a ruthenium complex compound having a pyrazine derivative represented by formula (II) shown below as a ligand: wherein R 5 and R 6 , which may be the same or different, each represent an alkyl group or a substituted alkyl group; R 7 and R 8 , which may be the same or different, each have the same meaning as R 1 , R 2 , and R 3 , or R 7 and R 8 are taken together to form a fused ring; and the asterisk * is as defined above.