| abstract |
A process for the preparation of an enantiomerically enriched 2-substituted succinic acid derivative of formula (2), comprises asymmetric hydrogenation of a dehydro precursor of formula (7) or (8), or a mixture thereof wherein R<1> and R<2> are each independently H, a salt-forming cation or an organic group of up to 30 C atoms, and R<3> and R<4> are each independently H or an organic group of up to 30 C atoms, or are linked to form a ring, provided that R<3> and R<4> are not both H, in the presence of a transition metal complex of a chiral phosphine ligand having the partial formula (10) wherein n is 0 to 6 and R represents at least one non-hydrogen organic group of up to 30 C atoms. |