反应详情

Ethyl 3-oxo-4,22-choladienate (2.39 g) was dissolved in 99% ethanol (170 ml) containing 0.9 g of potassium hydroxide. 10% Palladium on carbon containing 50% H2O (0.16 g) was added and the mixture was hydrogenated at room temperature and 1 atmosphere for about 3 hours (280 ml hydrogen was consumed). The catalyst was removed by filtration and water (20 ml) was added. After stirring for 3 days, acetic acid was added to pH 4, the solution was concentrated under reduced pressure to about 10 ml, and 20 ml of water was added. After stirring, the mixture crystallised. Filtration and washing with water gave 2.1 g of the title compound. 1H-NMR (CDCl3, 300 MHz), 0.67 (3H, s); 0.92 (3H, d); 1.00 (3H, s); 2.68 (1H, t).

1. customwas hydrogenated at room temperature
2. custom1 atmosphere for about 3 hours (280 ml hydrogen was consumed)
3. customThe catalyst was removed by filtration and water (20 ml)
4. additionwas added
5. additionacetic acid was added to pH 4
6. concentrationthe solution was concentrated under reduced pressure to about 10 ml, and 20 ml of water
7. additionwas added
8. stirringAfter stirring
9. customthe mixture crystallised
10. filtrationFiltration
11. washwashing with water