Oxygen → (S)-2-(4-Fluorophenyl)-3-methylbutyric acid

Participants

Reaction Steps

1.0 g (5.15 mmol) of 2-(p-fluorophenyl)-3-methylcrotonic acid and 0.52 g (5.15 mmol) of triethylamine were suspended in 6 ml of methanol in a glove box (O2 content <1 ppm) in a 30 ml autoclave at RT and a solution of 4.1 mg (0.0051 mmol) of Ru(OAc)2 ((R)-MeOPIPHEP) in 5 ml of methanol was added as the catalyst. The autoclave was sealed and the hydrogenation was carried out at 20° while stirring and under an initial pressure of 200 bar. The pressure decreased to about 190 bar during the reaction. After a reaction period of 21 hours a sample of the hydrogenation solution was evaporated at 50°/20 mbar and analyzed. There was obtained (S)-2-(p-fluorophenyl)-3-methylbutanoic acid with an ee of 93%.

Provenance & Evidence