Formation of the diastereoisomeric salts with (R)-alpha-methylbenzylamine (II), followed by crystallization from methanol/toluene, provided the desired (R)-phenylpropionic acid salt (III) in good enantiomeric purity, which was further enriched in the desired enantiomer by recrystallization from the same solvent. The chiral carboxylic acid was then liberated from the recrystallized methylbenzylamine salt (III) by acidification with HCl in a water/heptane two-phase system.

A different synthetic process consisted in the asymmetric olefin hydroformylation of 2-fluoro-4-vinylbiphenyl (IV) using a Rh4(CO)12 in the presence of the chiral catalyst (2R,4R)-di[2,2'-(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl)]-2,4-pentyl diphosphite under a pressurized atmosphere of CO/H2. The resultant chiral aldehyde (V) was further oxidized to the corresponding carboxylic acid employing several different oxidant reagents.