反应详情

A solution of commercially available (S)-2-hydroxy-3-phenylpropionic acid (5.0 g, 30.1 mmol) and p-toluenesulfonic acid hydrate (1 g) in methanol (125 mL) was refluxed with removal of water using 3A molecular sieves for 17 h. The solution was concentrated and dissolved in ether. The ether solution was washed with saturated sodium bicarbonate, brine and concentrated to provide the title compound as a white solid (5.32 g, 98%): NMR (CDC13); δ 7.36-7.20 (m, 5H), 4.47 (ddd, J=5, 6, 7 Hz, 1H), 3.78 (s, 3H), 3.14 (dd, J=5, 14 Hz, 1H), 2.97 (dd, J=7, 14 Hz), 2.69 (d, J=6Hz, 1H).

1. concentrationThe solution was concentrated
2. dissolutiondissolved in ether
3. washThe ether solution was washed with saturated sodium bicarbonate, brine
4. concentrationconcentrated