反应详情

To a solution of 14 (22.0 g, 70 mmole) in 95% ethanol (200 ml) was added concentrated HCl (12 ml) and 10% palladium on activated carbon (2.0 g). The mixture was hydrogenated at an initial pressure of 50 psi until the uptake of hydrogen ceased. The mixture was filtered from the catalyst and the filtrate evaporated to a small volume. The residue was dissolved in water, the solution made basic with concentrated NH4OH and extracted with three portions of chloroform. The chloroform extracts were washed with dilute NH4OH, dried and evaporated to a thick syrup which crystallized on the addition of ethyl acetate. The crystals were collected and dried to give 14.4 g (65%) of 16a as white needles, mp 163°-165°. Recrystallization from acetone gave analytically pure 16a as the hemi-acetone solvate, 166°-167° NMR: δ 6.55, s, 2H (aromatic); 6.40, broad, 1H (hydroxyl H); 4.22, d, 1H (H-5α, J=13 Hz); 3.77 (CH3O--); 2.38 (CH3N); 0.87, d, 3H (7α-CH3, J=6.5 Hz).

1. filtrationThe mixture was filtered from the catalyst
2. customthe filtrate evaporated to a small volume
3. dissolutionThe residue was dissolved in water
4. extractionextracted with three portions of chloroform
5. washThe chloroform extracts were washed with dilute NH4OH
6. customdried
7. customevaporated to a thick syrup which
8. customcrystallized on the addition of ethyl acetate
9. customThe crystals were collected
10. customdried