Tetrabutylammonium Fluoride → (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(6,6-bis(isopropoxycarbonyl)spiro[3.3]hept-1-en-2-yl)-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

HRID 1400979Notes

Reaction equation

HRID 1400979 reaction equation
[Si]([O:8][C:9]([C@:11]12[CH2:55][CH2:54][C@@H:53]([C:56]([CH3:58])=[CH2:57])[C@@H:12]1[C@@H:13]1[C@@:26]([CH3:29])([CH2:27][CH2:28]2)[C@@:25]2([CH3:30])[C@@H:16]([C@:17]3([CH3:52])[C@@H:22]([CH2:23][CH2:24]2)[C:21]([CH3:32])([CH3:31])[C:20]([C:33]2[CH2:51][C:35]4([CH2:38][C:37]([C:45]([O:47][CH:48]([CH3:50])[CH3:49])=[O:46])([C:39]([O:41][CH:42]([CH3:44])[CH3:43])=[O:40])[CH2:36]4)[CH:34]=2)=[CH:19][CH2:18]3)[CH2:15][CH2:14]1)=[O:10])(C(C)(C)C)(C)C.CCCC[N+](CCCC)(CCCC)CCCC.[F-]>C1COCC1.Cl>[CH:48]([O:47][C:45]([C:37]1([C:39]([O:41][CH:42]([CH3:44])[CH3:43])=[O:40])[CH2:38][C:35]2([CH:34]=[C:33]([C:20]3[C:21]([CH3:32])([CH3:31])[C@H:22]4[C@:17]([CH3:52])([CH2:18][CH:19]=3)[C@@H:16]3[C@:25]([CH3:30])([C@@:26]5([CH3:29])[C@H:13]([CH2:14][CH2:15]3)[C@H:12]3[C@H:53]([C:56]([CH3:58])=[CH2:57])[CH2:54][CH2:55][C@:11]3([C:9]([OH:10])=[O:8])[CH2:28][CH2:27]5)[CH2:24][CH2:23]4)[CH2:51]2)[CH2:36]1)=[O:46])([CH3:50])[CH3:49]

Participants

5

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 86692325diisopropyl 6-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(((tert-butyldimethylsilyl)oxy)carbonyl)-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]chrysen-9-yl)spiro[3.3]hept-5-ene-2,2-dicarboxylate

Product 1

HCID 86692327(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(6,6-bis(isopropoxycarbonyl)spiro[3.3]hept-1-en-2-yl)-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 acidYield 100%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of diisopropyl 6-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(((tert-butyldimethylsilyl)oxy)carbonyl)-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]chrysen-9-yl)spiro[3.3]hept-5-ene-2,2-dicarboxylate (0.026 g, 0.021 mmol (based on 65% purity)) in THF (2 mL) was added TBAF (75% in water) (10.81 mg, 0.031 mmol). The mixture was stirred at rt for 30 minutes, then was diluted with 15 mL of 1N HCl and was extracted with ethyl acetate (3×20 mL). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure to give (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(6,6-bis(isopropoxycarbonyl)spiro[3.3]hept-1-en-2-yl)-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 (0.024 g, 0.021 mmol (based on 60% purity), 100% yield). The material was used in the next step with no additional purification. LCMS: m/e 701.5 (M−H)−, 3.35 min (method 3). 1H NMR (400 MHz, chloroform-d) δ=10.58 (br. s., 1H), 5.87 (s, 1H), 5.52 (d, J=4.8 Hz, 1H), 5.13-5.02 (m, 2H), 4.75 (s, 1H), 4.62 (br. s., 1H), 3.07-2.97 (m, 1H), 2.70 (s, 4H), 2.63-2.55 (m, 2H), 1.70 (s, 3H), 2.54-0.77 (m, 49H). The material was used in the next step with no additional purification.

Workup

  1. extractionwas extracted with ethyl acetate (3×20 mL)
  2. washThe combined organic layers were washed with brine
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-4ef7f92a3c894c8185a9b5c1525a993b
Source dataset
uspto-grants-2014_12
Patent number
US08906889B2

Reaction notes

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