The present invention relates to a process for the preparation of an
optically active carbonyl compound by
asymmetric hydrogenation of a prochiral α,β-unsaturated carbonyl compound with
hydrogen in the presence of at least one
optically active transition metal catalyst that is soluble in the reaction mixture and which has
rhodium as catalytically active
transition metal and a chiral, bidentate bisphosphine ligand, wherein the reaction mixture during the hydrogenation of the prochiral α,β-unsaturated carbonyl compound additionally comprises at least one compound of the general formula (I):in whichR1, R2: are identical or different and are C6- to C10-
aryl which is unsubstituted or carries one or more, e.g. 1, 2, 3, 4 or 5, substituents which are selected from C1- to C6-
alkyl, C3- to C6-cycloalkyl, C6- to C10-
aryl, C1- to C6-alkoxy and amino;Z is a group CHR3R4 or
aryl which is unsubstituted or carries one or more, e.g. 1, 2, 3, 4 or 5, substituents which are selected from C1- to C6-
alkyl, C3- to C6-cycloalkyl, C6- to C10-aryl, C1- to C6-alkoxy and amino, wherein R3 and R4 are as defined in the claims and the description.