反应详情

Trifluoroacetic acid (0.136 mL) was added to a solution of N-benzyl-N-(methoxymethyl)-N-trimethylsilylamine (43.9 g, 185 mmol) and γ-crotonolactone (12.5 g, 176 mmol) in 1,2-dichloromethane (176 mL), and the mixture was stirred in a nitrogen atmosphere at room temperature for four hours. A saturated sodium bicarbonate solution (250 mL) was added to the reaction solution, followed by extraction with chloroform (200 mL×2). The organic layer was washed with brine (400 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→90:10→84:16→80:20→75:25→66:34→50:50) to give 37.1 g of the title compound.

1. extractionfollowed by extraction with chloroform (200 mL×2)
2. washThe organic layer was washed with brine (400 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationAfter filtration
5. concentrationthe filtrate was concentrated under reduced pressure
6. customThe resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→90:10→84:16→80:20→75:25→66:34→50:50)