反应详情

To a solution of the compound 19 (200 mg, 0.580 mmol) in tetrahydrofuran (1 mL) under ice-cooling was added pivaloyl isocyanate (5 eq.), and stirred at the same temperature for 1 hour. After removing condenser, the reaction mixture was stirred at room temperature for 1 hour. The reaction mixture was partitioned between ethyl acetate and phosphate buffer (pH 7.0). The organic layer was separated, washed with water, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column (eluate: hexane - ether (2:1)) to give the compound 81 (227 mg, 83%) as crystals. Mp. 157-159° C. Rf 0.31 (1:2 EtOAc-hexane).

1. customAfter removing condenser
2. stirringthe reaction mixture was stirred at room temperature for 1 hour
3. customThe reaction mixture was partitioned between ethyl acetate and phosphate buffer (pH 7.0)
4. customThe organic layer was separated
5. washwashed with water
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by chromatography on a silica gel column (eluate: hexane - ether (2:1))