A process for preparing a compound of formula VI, wherein R 1 and R 6 is hydrogen, substituted or unsubstituted alkyl substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; R 5 is OR 2, NR 2 R 3, SR 2, B(OR 2)(OR 3), or X" selected from F, Cl, Br, I, OCOR 2, OSO 2 R 2, wherein R 2 and R 3 independently from each other represent substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; or R 2 and R 3 cooperatively form a part of a 5- to 10-membered fused or unfused ring, optionally a chiral 5- to 10-membered fused or unfused ring; X is selected from F, Cl, Br, I; and * indicates a chiral center; by hydrogenation of a compound of formula V, wherein R 1, R 5, R 6 and X are as defined above; wherein hydrogenation is conducted in the presence of a catalyst selected from complexes comprising at least one transition metal, wherein dehalogenation occurs in less than 10 molar % relative to the molar amount of the compound of formula VI wherein the catalyst is selected from the group consisting of (1,5-cyclooctadiene) (pyridine)(tricyclohexyl-phosphine) iridium hexafluorophosphate; (1,5-cyclooctadiene)iridium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate -2-(1-(bis(2,6-dimethylphenyl)phosphino)-2-methylpropan-2-yl)-4-tert-butyl-4,5-dihydrooxazole; (1,5-cyclooctadiene)iridium tetrakis[3,5-bis (trifluoromethyl)phenyl]borate -4-tert-butyl-2-(2-(diphenylphosphino)phenyl)-4,5-dihydro-oxazole; (1,5-cyclooctadiene)iridium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (4 S, 5 S)-4-(2-(dicyclohexylphosphinooxy)-1,3-diphenylpropan-2-yl)-5-methyl-2-phenyl-4,5-dihydrooxazole; (1,5-cyclooctadiene)iridium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ( R, R)-P,N-ferrocene oxazoline; (1,5-cyclooctadiene)iridium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ( R, R)-P,N-ferrocene imidazoline, (1,5-cyclooctadiene)iridium tetrakis[3,5-bis-(trifluoromethyl)phenyl]borate benzoyl-( R, R)-P,N-ferrocene imidazoline, bis(1,5-cyclooctadiene) diiridium dichloride -(+)-2,2',6,6'-tetramethoxy-4,4'-bis(diphenylphosphino)-3,3'-bipyridine; bis(1,5-cyclooctadiene)diiridium dichloride -2,2',6,6'-tetramethoxy-bis[di(3,5-dimethylphenyl)phosphino]-3,3'-bipyridine; bis(1,5-cyclooctadiene) dirhodium dichloride -2,2',6,6'-tetramethoxy-bis[di(3,5-dimethylphenyl) phosphino]-3,3'-bipyridine; bis(cycloocta-1,5-diene)rhodium tetrafluoroborate -4,12-bis(diphenylphosphino)-[2.2]-paracyclophane; benzeneruthenium dichloride dimer 1- -N-methyl-N-(diphenylphosphino)-1-[ -(diphenylphosphino)-ferrocenyl] ethylamine and bis(2-methylallyl)(1,5-cyclooctadien)ruthenium -(+)-4,12-bis[di(3,5-dimethylphenyl)phosphino]-[2.2]paracyclophane. R 1 and R 6 is hydrogen, substituted or unsubstituted alkyl substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; R 5 is OR 2, NR 2 R 3, SR 2, B(OR 2)(OR 3), or X" selected from F, Cl, Br, I, OCOR 2, OSO 2 R 2, wherein R 2 and R 3 independently from each other represent substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; or R 2 and R 3 cooperatively form a part of a 5- to 10-membered fused or unfused ring, optionally a chiral 5- to 10-membered fused or unfused ring; X is selected from F, Cl, Br, I; and * indicates a chiral center;