反应详情

温度

115 °C

To a solution of methyl 3-ketopentanoate (3) (822 mg, 6.00 mmol) and 2-propynol (686 mg, 12.0 mmol) in toluene (7 mL) is added I2 (46 mg, 0.18 mmol). The mixture is stirred at 115° C. for 6 h, then cooled to room temperature, and extracted with ethyl acetate (100 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is distilled (125-130° C., 2 mm) to give 401 mg (43%) of 4 as a colorless liquid. IR 3345, 2856, 1715, 1456 cm−1; 1H NMR (CDCl3) δ 1.10 (t, J=7.5 Hz, 3H, CH2CH3), 2.52 (t, J=2.4 Hz, 1H, CH≡CCH2), 2.58 (q, J=7.5 Hz, 2H, CH2CH3) 3.51 (s, 2H, CH2), 4.74 (d, J=2.4 Hz, 2H, CH≡CCH2).

1. temperaturecooled to room temperature
2. extractionextracted with ethyl acetate (100 mL)
3. washThe extract is washed (brine)
4. customdried
5. customAfter solvent removal at reduced pressure
6. distillationthe residue is distilled (125-130° C., 2 mm)