3-Phenylbutyric acid → 4-Phenylpentan-2-one

Participants

Reaction Steps

1.6 M Methyl lithium (22.8 mL, 36.5 mmol) was added over 1 hour to a stirring 0° C. solution of 3-Phenylbutyric acid (1.8298 g, 11.14 mmol) in dry Et2O (56 mL, 0.2 M): The ice bath was removed, and the reaction was allowed to stir at room temperature for 2⅔ additional hours. Another 0.8 mL MeLi (1.12 mmol, 0.10 equiv) was added, and the reaction was stirred for another 30 minutes. The reaction was then poured into rapidly stirring ice water containing aq. HCl. The organic layer was removed, washed with NaHCO3 and brine, then dried with Na2SO4, filtered and concentrated to achieve pure 55 (1.2324 g, 68.2%): 1H (CDCl3, 400 MHz): δ 7.30 (2H, t, J=7.3 Hz), 7.22 (2H, d, J=7.3 Hz), 7.20 (2H, t, J=7.3 Hz), 3.37-3.27 (1H, m), 2.76 (1H, dd, J=16.1, 6.3 Hz), 2.66 (1H, dd, J=16.1, 7.8 Hz), 2.05 (3H, s), 1.28 (3H, d, J=7.3 Hz) ppm. 13C (CDCl3, 100 MHz): δ 208.01, 146.42, 128.80, 127.03, 126.57, 52.16, 35.67, 30.77, 22.28 ppm. DEPT (CDCl3, 100 MHz): CH3 carbons: 30.77, 22.28; CH2 carbons: 52.16; CH carbons: 128.80, 127.03, 126.57, 35.67 ppm. HPLC: 10.017 min. (Note: SM has HPLC retention time of 9.041 min.)

Provenance & Evidence