反应详情

Acetic anhydride (0.18 mL, 1.9 mmol) was added at 0° C. to 264a) (0.45 g, 0.94 mmol) in pyridine (2.0 mL) and the resulting solution was stirred at room temperature for 3 h. The reaction mixture was diluted with cold water and extracted with dichloromethane/methanol (9:1; 3×30 mL). The organic layers were washed with saturated sodium hydrogen carbonate solution (2×20 mL) and brine (20 mL), dried over sodium sulfate and evaporated. The remnant was purified by flash column chromatography [silica; dichloromethane with 1.5% methanol]. Yield: 0.09 g (38% of theory)

1. extractionextracted with dichloromethane/methanol (9:1; 3×30 mL)
2. washThe organic layers were washed with saturated sodium hydrogen carbonate solution (2×20 mL) and brine (20 mL)
3. dry with materialdried over sodium sulfate
4. customevaporated
5. customThe remnant was purified by flash column chromatography [silica; dichloromethane with 1.5% methanol]