反应详情

A suspension of the product of part (i) (4.0 g, 12 mmole) in ethanol (150 ml) was hydrogenated at 45 p.s.i. (310 kPa) over 5% platinum on carbon (0.1 g) for 5 hours. After this time an additional portion of the catalyst (0.1 g) was added and hydrogenation was continued at room temperature for a further 48 hours. The catalyst was removed by filtration and the filtrate concentrated under reduced pressure. The dark residue was purified by flash chromatography on silica gel eluting with ethyl acetate (97):methanol (3) to yield, after collection and evaporation of appropriate fractions, the desired product, m.p. 134°-135° (1.2 g, 33%), which was used without further purification.

1. customThe catalyst was removed by filtration
2. concentrationthe filtrate concentrated under reduced pressure
3. customThe dark residue was purified by flash chromatography on silica gel eluting with ethyl acetate (97)
4. custommethanol (3) to yield
5. customafter collection and evaporation of appropriate fractions
6. customthe desired product, m.p. 134°-135° (1.2 g, 33%), which was used without further purification