반응 #494067

반응 방정식

(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

→

(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

수율 99.1%

용매

Dioxane

HCl

water

반응 조건

후처리

1. 1
   추출extracted with dichloromethane (3×100 mL)
2. 2
   건조The combined organic layers were dried with Na2SO4
3. 3
   여과filtered
4. 4
   농축partially concentrated under reduced pressure to a volume of 10 mL
5. 5
   workup.ADDITIONTo the partially concentrated mixture was added 1N HCl (50 mL)
6. 6
   기타The solids that formed
7. 7
   여과were collected by filtration
8. 8
   세척were washed with water

실험 절차

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

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