反应详情

A solution of crude 22 (2.66 mmol) in toluene (60 mL) was treated with para-toluenesulfonic acid (20 mg) and refluxed under a Dean-Stark trap for 1.5 hrs. After cooling, the reaction mixture was diluted with ethyl acetate (100 mL) and washed with saturated sodium bicarbonate (100 mL) and water (100 mL). The solvent was removed in a rotary evaporator and the crude product was purified by chromatography on silica (40 g) with hexane (2 L) and 1% ethyl acetate in hexane (2 L) to afford pure 23 (0.12 g) and impure 23 (0.50 g).

1. temperaturerefluxed under a Dean-Stark trap for 1.5 hrs
2. temperatureAfter cooling
3. washwashed with saturated sodium bicarbonate (100 mL) and water (100 mL)
4. customThe solvent was removed in a rotary evaporator
5. customthe crude product was purified by chromatography on silica (40 g) with hexane (2 L) and 1% ethyl acetate in hexane (2 L)