反应详情

温度

-78 °C

To a suspension of lithium aluminium hydride (17.1, 0.45 mol) in tetrahydrofuran (700 mL) at −78° C. was added drop-wise a solution of 1-cyclopropylpent-4-en-2-one (C64) (38 g, 0.3 mol) in tetrahydrofuran (100 mL). After the addition, the mixture was stirred at −78° C. for 1 hour. The reaction mixture was quenched with water (20 mL) at −78° C., then dichloromethane (200 mL) was added and the mixture was stirred at room temperature for 0.5 hours. The mixture was filtered, the filter cake was washed with dichloromethane (2×200 mL), and the combined filtrates were dried and concentrated in vacuo to give crude product; purification via silica gel chromatography (Gradient: 0% to 10% ethyl acetate in petroleum ether) afforded the product as a yellow oil. Yield: 16 g, 127 mmol, 43% over 2 steps. 1H NMR (400 MHz, CDCl3) δ 5.81-5.87 (m, 1H), 5.01-5.14 (m, 2H), 3.75 (m, 1H), 2.30-2.34 (m, 1H), 2.18-2.23 (m, 1H), 1.34-1.43 (m, 2H), 0.68-0.80 (m, 1H), 0.39-0.49 (m, 2H), 0.02-0.15 (m, 2H).

1. additionAfter the addition
2. customThe reaction mixture was quenched with water (20 mL) at −78° C.
3. additiondichloromethane (200 mL) was added
4. stirringthe mixture was stirred at room temperature for 0.5 hours
5. filtrationThe mixture was filtered
6. washthe filter cake was washed with dichloromethane (2×200 mL)
7. customthe combined filtrates were dried
8. concentrationconcentrated in vacuo
9. customto give crude product
10. custompurification via silica gel chromatography (Gradient: 0% to 10% ethyl acetate in petroleum ether)