反应详情

温度

60 °C

To a solution of (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-benzyl 9-(4-(methoxycarbonyl)phenyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate (3.82 g, 5.76 mmol) in dichloroethane (100 mL) was added triethylamine (1.285 mL, 9.22 mmol), tert-butyldimethylsilane (1.912 mL, 11.52 mmol), and palladium(II) acetate (0.647 g, 2.88 mmol). The mixture was flushed with N2 and heated to 60° C. After 2 h, the reaction was cooled to rt, filtered through a pad of celite and silica gel to remove the solids which were washed with 25% EtOAc in hexanes. The filtrate was concentrated under reduced pressure and treated with acetic acid (25 mL), THF (10 mL) and water (3 mL). After stirring for 1 h the solids formed were collected by filtration and washed with water to give the title compound (3.62 g, 5.27 mmol, 91% yield) as a white solid. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.94 (d, J=8.28 Hz, 2H), 7.21 (d, J=8.28 Hz, 2H), 5.30 (dd, J=6.15, 1.63 Hz, 1H), 4.75 (d, J=1.76 Hz, 1H), 4.62 (s, 1H), 3.92 (s, 4H), 3.08 (td, J=10.92, 4.27 Hz, 1H), 2.35-2.22 (m, 2H), 2.17-2.06 (m, 1H), 2.02-1.84 (m, 2H), 1.71 (s, 3H), 1.01 (s, 6H), 0.99 (br. s., 3H), 0.98 (s, 9H), 0.94 (s, 6H), 1.78-0.90 (m, 16H), 0.32-0.28 (m, 6H).

1. customThe mixture was flushed with N2
2. temperaturethe reaction was cooled to rt
3. filtrationfiltered through a pad of celite and silica gel
4. customto remove the solids which
5. washwere washed with 25% EtOAc in hexanes
6. concentrationThe filtrate was concentrated under reduced pressure
7. additiontreated with acetic acid (25 mL), THF (10 mL) and water (3 mL)
8. customformed
9. filtrationwere collected by filtration
10. washwashed with water