反应详情

A solution of ethyl glyoxalate (27 mL, 0.14 mol) and 4-chlorobenzene sulfonylisocyanate (20 mL, 0.14 mol) in toluene (300 mL) was heated at reflux for 60 hours. The reaction mixture was cooled to room temperature and 1-methoxy-3-trimethylsilyl-1,3-butadiene (27 mL, 0.14 mol) was added, The reaction was heated at 50° C. for 18 hours. The reaction mixture was concentrated in vacuo and the residue was purified by flash chromatography (20% EtOAc/hexanes) to yield 16.0 g (34%) of compound 103 as a yellow oil. 1H NMR (CDCl3) δ 7.81 (d, 2H), 7.67 (dd, 1H), 7.55 (d, 2H), 5.40 (d, 1H), 5.01-4.97 (m, 1H), 4.13-4.03 (m, 3H), 2.86-2.81 (m, 2H), 1.16 (t, 3H).

1. temperatureat reflux for 60 hours
2. temperatureThe reaction was heated at 50° C. for 18 hours
3. concentrationThe reaction mixture was concentrated in vacuo
4. customthe residue was purified by flash chromatography (20% EtOAc/hexanes)