反应详情

To a solution of the compound of Example 542 (400 mg, 0.76 mmol) and triethylamine (0.29 mL, 2.1 mmol) in THF (17 mL) was added acetoxyacetyl chloride (0.10 mL, 0.95 mmol) under ice-cooling, and the mixture was stirred at room temperature for 4 hr. The reaction mixture was diluted with saturated aqueous sodium hydrogen carbonate solution, and extracted twice with ethyl acetate. The extract was combined, washed with saturated brine, dried over magnesium sulfate, and filtered through aminosilica gel. The filtrate was concentrated, and the residue was recrystallized from ethanol-hexane to give the title compound (321 mg, 71%) as a white solid.

1. temperaturecooling
2. extractionextracted twice with ethyl acetate
3. washwashed with saturated brine
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered through aminosilica gel
6. concentrationThe filtrate was concentrated
7. customthe residue was recrystallized from ethanol-hexane