反应详情

A stirred suspension of zinc (0.981 g, 15.00 mmol) in a solution of benzaldehyde (0.531 g, 5 mmol) and ethyl 2-bromo-2,2-difluoroacetate (1.522 g, 7.50 mmol) in an. THF (10 mL) was sonicated for 4-5 h and then stirred at rt overnight. The reaction was cooled and diluted with ether and washed with 1 N HCl, water, brine and dried (MgSO4). Evaporation of solvents afforded a clear oil which was purified by silica gel FCC (0-10% EtOAc in DCM) to afford ethyl 2,2-difluoro-3-hydroxy-3-phenylpropanoate as a clear oil (619 mg, ˜54%). 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 7.49-7.44 (m, 2H), 7.43-7.39 (m, 3H), 5.23-5.12 (m, J=15.3, 8.0, 5.5 Hz, 1H), 4.32 (q, J=7.1 Hz, 2H), 2.87-2.76 (m, 1H), 1.31 (t, J=7.2 Hz, 3H).

1. temperatureThe reaction was cooled
2. washwashed with 1 N HCl, water, brine
3. dry with materialdried (MgSO4)
4. customEvaporation of solvents
5. customafforded a clear oil which
6. customwas purified by silica gel FCC (0-10% EtOAc in DCM)