反应详情

Methyl (2S)-5-acetyl-2-ethyl-2,3-dihydro-benzofuran-2-carboxylate (3.8 g, ca. 15 mmol), m-chloroperbenzoic acid (70%, 7.7 g, 30 mmol) and NaHCO3 (3.8 g, 45 mmol) in dichloromethane (150 mL) was stirred under reflux for 2 hrs. The reaction mixture was washed successively with saturated aqueous sodium sulfite (100 mL) and aqueous NaHCO3 (2×100 mL). After removal of solvent, the residue was dissolved in methanol (100 mL) and treated with aqueous KOH (5 N, 3 mL) at 0° C. for 5 min. The reaction was neutralized with excess solid sodium bicarbonate, filtered and concentrated. The residue was purified by chromatography on silica gel eluting with 8:2 hexane:ethyl acetate to give the title compound.

1. temperatureunder reflux for 2 hrs
2. washThe reaction mixture was washed successively with saturated aqueous sodium sulfite (100 mL) and aqueous NaHCO3 (2×100 mL)
3. customAfter removal of solvent
4. dissolutionthe residue was dissolved in methanol (100 mL)
5. additiontreated with aqueous KOH (5 N, 3 mL) at 0° C. for 5 min
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by chromatography on silica gel eluting with 8:2 hexane