反应详情

温度

0 °C

To a stirred solution of diisopropylamine (7.7 mL, 0.055 mol) in tetrahydrofuran (80 mL), n-butyl lithium (1.59 M in cyclohexane, 34 mL, 0.055 mol) was added slowly at −70° C. and the mixture was stirred for 20 min at 0° C. The mixture was cooled to −78° C. and tert-butyl cyclopropanecarboxylate (6.5 g, 0.046 mol, Kohlrausch et al., Z. Elektrochem. Angew. Phys. Chem., 1937, 70, 392) in tetrahydrofuran (10 mL) was added dropwise, and the mixture was stirred for 3 h. Then, diiodomethane (4.0 mL, 0.050 mol) in tetrahydrofuran (10 mL) was added dropwise, and the mixture was allowed to warm up to room temperature overnight. Saturated aqueous NH4Cl (80 mL) was added to the solution and it was extracted with diethyl ether (50 mL), washed with brine (20 mL), dried over MgSO4, filtered and concentrated to give brown oil. The oil was chromatographed on a column of silica gel eluting with hexane/diethyl ether (40:1) to give 1.9 g of the title compound as a crude product. The crude product was used without further purification. Rf: 0.3 (hexane/diethyl ether (40:1))

1. temperatureThe mixture was cooled to −78° C.
2. stirringthe mixture was stirred for 3 h
3. temperatureto warm up to room temperature overnight
4. extractionwas extracted with diethyl ether (50 mL)
5. washwashed with brine (20 mL)
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customto give brown oil
10. customThe oil was chromatographed on a column of silica gel eluting with hexane/diethyl ether (40:1)