反应详情

温度

0 °C

To a solution of (3aS,4R,5R,6S,7aS)-6-formyl-2-oxooctahydrobenzo[d]oxazole-4,5-diyl dibenzoate (580 mg, 1.42 mmol) in dry DCM (10 mL) at 0° C. under N2 was added a solution of acetyl chloride (223 mg, 2.84 mmol) in dry DCM (2.84 mL) followed by a solution of DIPEA (330 mg, 2.56 mmol) in dry DCM (2.56 mL) dropwise. The mixture was stirred at 0° C. for 2 h. The reaction was further diluted with DCM (20 mL), washed with 0.1 N HCl and brine. The solvent was evaporated to give the crude (3aS,4R,5R,6S,7aS)-3-acetyl-6-formyl-2-oxooctahydrobenzo[d]oxazole-4,5-diyl dibenzoate (614 mg, 96%) which was carried onto next reaction without further purification. 1H NMR (400 MHz, CDCl3) δ 9.89 (s, 1H), 7.93 (d, J=7.8 Hz, 2H), 7.90 (d, J=7.8 Hz, 2H), 7.54-7.59 (m, 2H), 7.40-7.44 (m, 4H), 5.79 (dd, J=5.7 Hz, 4.1 Hz, 1H), 5.68 (t, J=5.7 Hz, 1H), 5.01-5.04 (m, 1H), 4.82 (dd, J=7.7 Hz, 4.0 Hz, 1H), 3.13-3.19 (m, 1H), 2.54-2.60 (m, 1H), 2.50 (s, 3H), 2.26-2.34 (m, 1H).

1. washwashed with 0.1 N HCl and brine
2. customThe solvent was evaporated