反应详情

To a solution of cyano-cyclohexylidene-acetic acid ethyl ester (1.37 g, 7.09 mmol) in 30 mL acetonitrile was added nitromethane (1.92 mL, 35.5 mmol), followed by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (1.06 mL, 7.09 mmol) resulting in an orange solution. The reaction was stirred for 2.5 hours, then partitioned between ethyl ether (Et2O) and 1N hydrochloric acid (HCl) (aq). The phases were separated, and the organic phase washed with brine, dried over magnesium sulfate (MgSO4), and concentrated. Flash chromatography of the residue (5% ethyl acetate (EtOAc)/hexanes) afforded 1.1 g (75%) of 1-cyano-spiro[2.5]octane-1-carboxylic acid ethyl ester as a colorless oil. 1H NMR (CDCl3) δ 4.22 (m, 2H), 1.77 (d, J=5.1 Hz, 1H), 1.42–1.72 (m, 10H), 1.40 (d, J=5.1 Hz, 1H), 1.30 (t, J=7.1 Hz, 3H). 13C NMR δ 166.40, 118.60, 62.72, 40.20, 34.67, 29.01, 28.75, 25.69, 25.54, 25.28, 24.66, 14.38. LRMS: m/z 208.0 (M+1). IR: 2239, 1732 cm−1. Anal. Calcd for C12H17NO2: C, 69.54; H, 8.27; N, 6.76. Found: C, 69.41; H, 8.33; N, 6.75.

1. customresulting in an orange solution
2. custompartitioned between ethyl ether (Et2O) and 1N hydrochloric acid (HCl) (aq)
3. customThe phases were separated
4. washthe organic phase washed with brine
5. dry with materialdried over magnesium sulfate (MgSO4)
6. concentrationconcentrated