反应详情

温度

25 °C

A solution of diazo-acetic acid ethyl ester (555 mg, 4.86 mmol) in dichloromethane (8 mL) was treated with tin (II) chloride (88 mg, 0.463 mmol) and stirred vigorously at 25° C. A solution of 4-methyl-pentanal (464 mg, 4.63 mmol) in dichloromethane (2 mL) was added to the mixture dropwise over 10 min resulting in gas evolution. After the nitrogen evolution ceased (approximately 1 h), the reaction was extracted with brine and diethyl ether (2×80 mL). The organic layers were combined, dried over sodium sulfate, filtered and concentrated in vacuo. The crude material was purified by flash column chromatography (ISCO RediSep column, 0 to 7% ethyl acetate in hexanes) to afford the desired product, 6-methyl-3-oxo-heptanoic acid ethyl ester (478 mg, 55%), as a light yellow oil. 1H NMR (400 MHz, CDCl3) δ: 0.89 (6H, d, J=6.3 Hz), 1.26-1.29 (4H, m), 1.48-1.57 (2H, m), 2.53 (2H, t, J=7.4 Hz), 3.42 (2H, s), 4.18 (2H, quartet, J=7.6 Hz).

1. customresulting in gas evolution
2. custom(approximately 1 h)
3. extractionthe reaction was extracted with brine and diethyl ether (2×80 mL)
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude material was purified by flash column chromatography (ISCO RediSep column, 0 to 7% ethyl acetate in hexanes)