反应详情

To a solution of 0.14 g (0.53 mmol) of 2 in 0.43 mL (2.6 mmol) of triethylorthoformate was added 0.25 mL (2.6 mmol) of acetic anhydride. The resulting solution was heated to reflux for 4 h before being concentrated to an oil. The crude oil thus obtained was purified by flash chromatography eluting with 75% hexanes/AcOEt to give 0.079 g (46%) of the title compound as a yellow oil. 1H NMR (CDCl3) δ 1.42 (t, J=7.2 Hz, 3H), 1.67-1.77 (m, 1H), 2.01-2.09 (m, 1H), 2.53-2.62 (m, 1H), 2.71 (d, J=7.4 Hz, 2H), 3.05 (dd, J=8.4, 9.8 Hz, 1H), 3.35-3.41 (m, 1H), 3.48 (dd, J=7.0, 9.5 Hz, 1H), 3.53-3.59 (m, 1H), 4.31 (q, J=7.2 Hz, 2H), 7.15-7.17 (m, 2H), 7.19-7.23 (m, 1H), 7.26-7.31 (m, 2H), 7.76 (s, 1H).

1. temperatureThe resulting solution was heated
2. temperatureto reflux for 4 h
3. concentrationbefore being concentrated to an oil
4. customThe crude oil thus obtained
5. customwas purified by flash chromatography
6. washeluting with 75% hexanes/AcOEt