反应详情

To a solution of L-valine benzylester in MeOH (12 mL) was slowly added 1,3-propanesultone (604 mg, 5.0 mmol). The solution was stirred at reflux for 2 hours. The reaction was cooled to room temperature. The solid was collected by filtration, washed with cold MeOH and acetone (2×25 mL). It was dried in the vacuum oven (50° C.), affording the title compound (649 mg, 39%). 1H NMR (D2O, 500 MHz) δ ppm 7.47 (m, 5H), 5.41 (d, 1H, J=11.7 Hz), 5.31 (d, 3H, J=11.7 Hz), 4.04 (m, 1H), 3.19 (m, 2H), 2.95 (t, 2H, J=6.8 Hz), 2.35 (m, 1H), 2.14 (m, 2H), 1.04 (d, 3H, J=6.3 Hz), 0.95 (d, 3H, J=6.3 Hz). 13C (D2O, 125 MHz) δ ppm 168.75, 134.81, 129.38, 129.31, 129.17, 69.00, 65.96, 48.24, 46.71, 29.67, 21.40, 18.39, 16.65. [α]D=−7.2° (c=0.0015 in water), ES-MS 330 (M+1).

1. temperatureat reflux for 2 hours
2. filtrationThe solid was collected by filtration
3. washwashed with cold MeOH and acetone (2×25 mL)
4. customIt was dried in the vacuum oven (50° C.)