反应详情

A 250-mL round-bottomed flask equipped with a magnetic stirrer and a Dean-Stark trap was charged with 287b (11.0 g, 1.0 eq., 64.7 mmol), hexane-2,5-dione (11.1 g, 1.5 eq., 97.2 mmol), p-toluenesulfonic acid monohydrate (558 mg, 0.05 eq., 3.24 mmol), and toluene (100 mL). The reaction mixture was refluxed overnight. The resulting mixture was cooled to room temperature and concentrated under reduced pressure. The resulting residue was purified by silica-gel column chromatography eluting with 1:2 petroleum ether/ethyl acetate to afford 287c (10.4 g, 65%) as white solid. MS-ESI: [M+H]+ 249.0

1. customA 250-mL round-bottomed flask equipped with a magnetic stirrer
2. temperatureThe reaction mixture was refluxed overnight
3. concentrationconcentrated under reduced pressure
4. customThe resulting residue was purified by silica-gel column chromatography
5. washeluting with 1:2 petroleum ether/ethyl acetate