Tetrabutylammonium Fluoride → (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-1-isopropenyl-9-(4-methoxycarbonylphenyl)-5a,5b,8,8,11a-pentamethyl-1,2,3,4,5,6,7,7a,11,11b,12,13,13a,13b-tetradecahydrocyclopenta[a]chrysene-3a-carboxylic acid

HRID 85551Notes

Reaction equation

HRID 85551 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]([C:11]2[C:12]([CH3:49])([CH3:48])[C@H:13]3[C@:26]([CH3:29])([CH2:27][CH:28]=2)[C@@H:25]2[C@:16]([CH3:47])([C@@:17]4([CH3:46])[C@H:22]([CH2:23][CH2:24]2)[C@H:21]2[C@H:30]([C:33]([CH3:35])=[CH2:34])[CH2:31][CH2:32][C@:20]2([C:36]([O:38][Si](C(C)(C)C)(C)C)=[O:37])[CH2:19][CH2:18]4)[CH2:15][CH2:14]3)=[CH:7][CH:6]=1)=[O:4].CCCC[N+](CCCC)(CCCC)CCCC.[F-]>O1CCOCC1.Cl.O>[CH3:1][O:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]([C:11]2[C:12]([CH3:49])([CH3:48])[C@H:13]3[C@:26]([CH3:29])([CH2:27][CH:28]=2)[C@@H:25]2[C@:16]([CH3:47])([C@@:17]4([CH3:46])[C@H:22]([CH2:23][CH2:24]2)[C@H:21]2[C@H:30]([C:33]([CH3:35])=[CH2:34])[CH2:31][CH2:32][C@:20]2([C:36]([OH:38])=[O:37])[CH2:19][CH2:18]4)[CH2:15][CH2:14]3)=[CH:7][CH:6]=1)=[O:4]

Participants

6

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 67776655(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

Product 1

HCID 54759950(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-1-isopropenyl-9-(4-methoxycarbonylphenyl)-5a,5b,8,8,11a-pentamethyl-1,2,3,4,5,6,7,7a,11,11b,12,13,13a,13b-tetradecahydrocyclopenta[a]chrysene-3a-carboxylic acidYield 99.1%

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

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).

Workup

  1. extractionextracted with dichloromethane (3×100 mL)
  2. dry with materialThe combined organic layers were dried over Na2SO4
  3. filtrationfiltered
  4. concentrationpartially concentrated under reduced pressure to about 10 mL volume
  5. additionTo the partially concentrated mixture was added 1N HCl (50 mL)
  6. customThe solids that formed
  7. filtrationwere collected by filtration
  8. washwashed with water

Sources & evidence

ORD record
ord-0f7564ddbfdf4047b2523defc8214a4f
Source dataset
uspto-grants-2014_09
Patent number
US08846647B2

Reaction notes

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