反应详情

Anhydrous THF (200 ml) was introduced into a dried two-necked flask to which sodium hydride (60 w/w %, 2.71 g, 67.8 mmol) was added. The temperature thereof was allowed to fall to 0° C., and t-butyl acetoacetate (9.00 g, 56.9 mmol) was added dropwise thereto. The resulting mixture was stirred for 10 minutes while maintaining the temperature thereof at 0° C., and then n-butyllithium (1.6M hexane solution, 39.1 ml, 62.6 mmol) was added dropwise. After the obtained mixture was stirred for 30 minutes at 0° C., 1-iodobutane (13.6 g, 73.9 mmol) was added thereto, and then stirred for 6 hours. A saturated ammonium chloride solution was added to the obtained mixture and extracted 3 times with diethyl ether. The resulting organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated. The obtained residue was purified by column chromatography (silica gel: 200 g, n-hexane/ethyl acetate=10/1) to produce the target compound (11.3 g, 73%).

1. additionwas added
2. customto fall to 0° C.
3. temperaturewhile maintaining the temperature
4. stirringAfter the obtained mixture was stirred for 30 minutes at 0° C.
5. stirringstirred for 6 hours
6. extractionextracted 3 times with diethyl ether
7. dry with materialThe resulting organic layer was dried with anhydrous magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe obtained residue was purified by column chromatography (silica gel: 200 g, n-hexane/ethyl acetate=10/1)