The synthesis of the first chiral polyhydroxy diphosphine-Rh(I) catalyst for asymmetric hydrogenation is described. Based on a simple synthetic pathway starting from d-mannitol the new metal complex is constructed. A specialfeature of the approach is the protection of the air-sensitive phosphine groups by the catalytically active metal in the final synthetic steps. Therefore, tedious P-protection-deprotection
derivatives of the prominent DuPHOS or BPE ligands. D-Mannitol was used as the starting material for these ligands. New bisphospholanes were used as ligands in the enantioselective rhodium(I)-catalyzedhydrogenation of functionalized olefins like unsaturated α- and β-amino acid derivatives, itaconates, and an unsaturated phosphonate. A relevant ruthenium(II) catalyst was used for the reduction of prochiral β-oxo