反応 #172733

反応方程式

(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-tert-butyldimethylsilyl 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

TBAF

→

title compound

収率 99.1%

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

収率 99.1%

溶媒

dioxane

HCl

water

反応条件

後処理

1. 1
   抽出extracted with dichloromethane (3×100 mL)
2. 2
   乾燥The combined organic layers were dried over Na2SO4
3. 3
   ろ過filtered
4. 4
   濃縮partially concentrated under reduced pressure to about 10 mL volume
5. 5
   workup.ADDITIONTo the partially concentrated mixture was added 1N HCl (50 mL)
6. 6
   その他The solids that formed
7. 7
   ろ過were collected by filtration
8. 8
   洗浄washed with water

実験手順

To solution of (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-tert-butyldimethylsilyl 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 (3.12 g, 4.54 mmol) in dioxane (25 mL) was added TBAF (75% wt in water) (2.375 g, 6.81 mmol) and the mixture was stirred at rt for 4 h. The reaction mixture was diluted with 1N HCl (25 mL) and water (5 mL) and extracted with dichloromethane (3×100 mL). The combined organic layers were dried over Na2SO4, filtered, and partially concentrated under reduced pressure to about 10 mL volume. To the partially concentrated mixture was added 1N HCl (50 mL). The solids that formed were collected by filtration and washed with water to give the title compound (2.58 g, 4.50 mmol, 99% yield) as a white solid. LCMS: m/e 571.47 (M−H)−, 3.60 min (method 1). 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 9.80 (br. s., 1H), 7.92 (d, J=8.24 Hz, 2H), 7.18 (d, J=8.24 Hz, 2H), 5.32-5.26 (m, 1H), 4.75 (s, 1H), 4.62 (br. s., 1H), 3.90 (s, 3H), 3.07-2.99 (m, 1H), 2.33-2.21 (m, 2H), 2.10 (dd, J=17.09, 6.10 Hz, 1H), 2.06-1.94 (m, 2H), 1.70 (s, 3H), 1.01 (br. s., 3H), 1.00 (br. s., 3H), 0.98 (s, 3H), 0.91 (s, 6H), 1.79-0.89 (m, 17H).

出典