Reacción #172873

Ecuación de reacción

(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-benzyl 9-(3-fluoro-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

t-butyldimethylsilane

TBAF

→

title compound

Rendimiento 95.0%

(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(3-fluoro-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-carboxylic acid

Rendimiento 95.0%

Disolventes

HCl

DCE

dioxane

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe mixture was flushed with N2
2. 2
   TemperaturaThe mixture was cooled to rt
3. 3
   Filtraciónwas filtered through a plug of celite and silica gel (washed with 25% EtOAc in hexanes)
4. 4
   ConcentraciónThe filtrate was concentrated under reduced pressure
5. 5
   workup.ADDITIONwas added
6. 6
   OtroThe solids that formed
7. 7
   Filtraciónwere collected by filtration
8. 8
   Lavadowere washed with water

Procedimiento

To a solution of (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-benzyl 9-(3-fluoro-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 (3.59 g, 5.27 mmol) in DCE (25 mL) was added TEA (1.176 mL, 8.44 mmol), t-butyldimethylsilane (1.749 mL, 10.54 mmol), and palladium(II) acetate (0.118 g, 0.527 mmol). The mixture was flushed with N2 and heated to 60° C. for 1 h. The mixture was cooled to rt and was filtered through a plug of celite and silica gel (washed with 25% EtOAc in hexanes). The filtrate was concentrated under reduced pressure. The residue was diluted with 25 mL of dioxane and TBAF (75% in water) (2.76 g, 7.91 mmol) was added. The mixture was stirred for 30 minutes at rt then was diluted with 50 mL of 1N HCl. The solids that formed were collected by filtration and were washed with water to give the title compound (2.95 g, 4.99 mmol, 95% yield) as a white solid. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.83 (1H, t, J=7.9 Hz), 6.90-7.00 (2H, m), 5.34 (1H, dd, J=6.1, 1.6 Hz), 4.77 (1H, d, J=2.0 Hz), 4.64 (1H, s), 3.94 (3H, s), 3.04 (1H, td, J=10.7, 4.8 Hz), 2.24-2.34 (2H, m), 2.13 (1H, dd, J=17.3, 6.3 Hz), 1.96-2.06 (2H, m), 1.72 (3H, s), 1.03 (3H, s), 1.02 (3H, s), 0.98 (3H, s), 0.93-0.96 (6H, m), 0.91-1.80 (17H, m).

Fuente