(R)-3-phenyllactic acid → (R)-3-phenylpropane-1,2-diol

Participants

Reaction Steps

To a solution of (R)-2-hydroxy-3-phenylpropanoic acid (5.0 g, 30.0 mmol) in 100 mL of anhydrous THF was added slowly BH3.THF complex (90 mL, 1M in THF, 3.0 equiv.) with ice cooling under N2. The solution was stirred overnight at room temperature, and the reaction was quenched with water (Caution, copious H2 evolution). After evaporation of the solvent, the residue was diluted with water and extracted with EtOAc (3×50 mL). The combined organic layers were dried over Na2SO4 and concentrated to afford (R)-3-phenylpropane-1,2-diol (4.3 g, 94%) as a colorless oil. LC-MS (ESI) m/z 153 (M+H+). 1H NMR (CDCl3, 300 MHz) δ 7.37-7.23 (m, 5H), 4.02-3.94 (m, 1H), 3.74 (dd, 1H, J=11.1, 3.3 Hz), 3.54 (dd, 1H, J=11.1, 6.9 Hz), 2.85-2.74 (m, 2H).

Provenance & Evidence