| abstract |
BICHEP, i.e., 2,2′-bis(dicyclohexylphosphinyl)-6,6′-dimethyl-1,1′-biphenyl of formula:n is prepared, in known manner and as described in an appplication [of the same date hereof], No. 90 and is recrystallised to constant optical rotation. A metal such as rhodium or ruthenium forms a phosphino complex with BICHEP as a ligand. n The complex is used as catalyst in a process of producing an optically active carboxylic acid or ester thereof of formula:n wherein R represents H or lower alkyl (C1-4); R¹ represents a lower alkyl, CH₂COOR³, wherein R³ is H or lower alkyl or NHR⁴, wherein R⁴ is formyl, acetyl, benzoyl or chloroacetyl and R² represents H, lower alkyl or phenyl, which comprises hydrogenating an unsaturated compound:n in an organic solvent at a hydrogen pressure of 1 - 100 kg/cm² at 5 to 70°C; the catalyst is removed and recovered. |