反应详情

1-(3,3-dimethoxycyclobutyl)pent-4-en-1-one (3.0, 15.1) was dissolved in 2,2,2-trifluoroethanol (7 mL). Ammonium acetate (4.66 g, 60.5 mmol) and tert-butyl isocyanide (3.40 mL, 30.3 mmol) were added and the reaction was stirred 3 days at room temperature. The reaction was diluted with ethyl acetate, washed successively with water, saturated aqueous sodium chloride, dried over MgSO4, and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 20-100% ethyl acetate in heptane to afford the desired product (4.04 g, 79%). Rf 0.16 (50% ethyl acetate in heptane). 1H NMR (CDCl3, 300 MHz) δ 7.10 (br s, 1H), 6.71 (br s, 1H), 5.83-5.69 (m, 1H), 5.03-4.91 (m, 2H), 3.14 (s, 6H), 2.91-2.72 (m, 2H), 2.39-2.24 (m, 2H), 2.13-1.79 (m, 7H), 1.53-1.33 (m, 10H). ESI MS found for C18H32N2O4 m/z [363.0 (M+Na+)].

1. washwashed successively with water, saturated aqueous sodium chloride
2. dry with materialdried over MgSO4
3. concentrationconcentrated in vacuo
4. customThe residue was chromatographed on silica gel eluting with 20-100% ethyl acetate in heptane