Ethanol → (S)-(+)-ethyl 2-methyl-5-phenylpentanoate

Participants

Reaction Steps

To a solution consisting of (S)-(+)-2-methyl-5-phenylpentanoic acid (20mb(i), 2.3 g, 12 mmol) in ethanol (200 mL) was added 4 drops of concentrated sulfuric acid. The stirring reaction mixture was brought to reflux overnight and was subsequently cooled and concentrated under vacuum. The residue was diluted with ethyl acetate and washed twice with brine. The organic layer was dried over sodium sulfate, filtered, and concentrated under vacuum to afford the title compound (2.4 g, 91%) as a clear oil; TLC Rf 0.66 (solvent system: 15:85:1 v/v/v ethyl acetate-heptane-acetic; MS (ESI+) m/z 221.2 (M+H)+; 1H-NMR (CDCl3) δ 7.29-7.25 (m, 2H), 7.21-7.13 (m, 3H), 4.12 (q, J=6.96 Hz, 2H), 2.64-2.57 (m, 2H), 2.48-2.39 (m, 1H), 1.75-1.54 (m, 3H), 1.52-1.41 (m, 1H), 1.24 (t, J=7.14 Hz, 3H) 1.16-1.11 (m, 3H); [α]Tλ=α/cl, [α]21.9D=+0.101/(0.01506 g/1.5 ml)(0.5)=+20.12° (c=1, CHCl3).

Provenance & Evidence