反应详情

To reactant (D)-Proline (4.6 g, 40 mmol) suspended in anhydrous acetonitrile (100 mL), was added 2,2,2-trichloroacetaldehyde (11.78 g, 80 mmol) slowly. The mixture was stirred at RT for 20 hour and was clear solution. After concentrated in vacuum, the residue was purified by CombiFlash on a 80 g silica gel column using EtOAC/Hexane as eluents to give (3S,7aR)-3-(trichloromethyl)tetrahydropyrrolo[1,2-c]oxazol-1(3H)-one 155a: 3.63 g, 37%. 1H NMR (400 MHz, Chloroform-d) δ 5.14 (s, 1H), 4.10 (dd, J=8.9, 4.7 Hz, 1H), 3.40 (ddd, J=10.9, 7.8, 6.0 Hz, 1H), 3.11 (dt, J=11.4, 6.0 Hz, 1H), 2.21 (dtd, J=13.0, 8.5, 6.8 Hz, 1H), 2.09 (ddt, J=12.7, 7.0, 5.2 Hz, 1H), 1.91 (ddq, J=12.4, 6.7, 5.7 Hz, 1H), 1.81-1.64 (m, 1H).

1. concentrationAfter concentrated in vacuum
2. customthe residue was purified by CombiFlash on a 80 g silica gel column