Potassium ethanethioate → 17-Acetylthiomethyl-1alpha,3beta-bis(tert-butyldimethylsilyloxy)androsta-5,7,16-triene

HRID 1014967Notes

Reaction equation

HRID 1014967 reaction equation
[Si:1]([O:8][C@@H:9]1[C@@:26]2([CH3:27])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:25]2[CH2:24][CH2:23][C@@:21]2([CH3:22])[C@H:17]3[CH2:18][CH:19]=[C:20]2[CH2:28]Br)[CH2:12][C@@H:11]([O:30][Si:31]([C:34]([CH3:37])([CH3:36])[CH3:35])([CH3:33])[CH3:32])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[C:38]([O-:41])(=[S:40])[CH3:39].[K+]>CC(C)=O.CCCCCC>[C:38]([S:40][CH2:28][C:20]1[C@:21]2([CH2:23][CH2:24][C@H:25]3[C:16](=[CH:15][CH:14]=[C:13]4[C@:26]3([CH3:27])[C@@H:9]([O:8][Si:1]([C:4]([CH3:6])([CH3:5])[CH3:7])([CH3:3])[CH3:2])[CH2:10][C@H:11]([O:30][Si:31]([C:34]([CH3:36])([CH3:37])[CH3:35])([CH3:33])[CH3:32])[CH2:12]4)[C@@H:17]2[CH2:18][CH:19]=1)[CH3:22])(=[O:41])[CH3:39]

Participants

5

Reactant 2

HCID 23670855Potassium ethanethioateHCID 673014911alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(bromomethyl)androsta-5,7,16-triene

Product 1

HCID 8658997017-Acetylthiomethyl-1alpha,3beta-bis(tert-butyldimethylsilyloxy)androsta-5,7,16-trieneYield 64%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 8058HexaneSolvent

Procedure

To a solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(hydroxymethyl)androsta-5,7,16-triene (100 mg, 0.183 mmol), triphenylphosphine (96.0 mg, 0.366 mmol) and imidazole (49.8 mg, 0.732 mmol) in dichloromethane (2 ml), N-bromosuccinimide (65.1 mg, 0.366 mmol) was added at 0° C. and stirred at room temperature. After 1 hour, hexane was added to the reaction mixture, which was then washed with water and saturated aqueous sodium chloride. After drying over anhydrous magnesium sulfate, the solvent was removed under reduced pressure to give a mixture (150 mg) containing 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(bromomethyl)androsta-5,7,16-triene. This mixture was dissolved in acetone (1.5 ml), followed by addition of potassium thioacetate (31.4 mg, 0.275 mmol) and stirring for 30 minutes. The reaction mixture was diluted with hexane and filtered. The resulting filtrate was evaporated under reduced pressure to remove the solvent and the residue was purified by preparative thin layer chromatography (0.5 mm×2 plates, hexane:ethyl acetate=20:1, developed once) to give the titled compound (70.2 mg, 64%) as a colorless oil.

Workup

  1. filtrationfiltered
  2. customThe resulting filtrate was evaporated under reduced pressure
  3. customto remove the solvent
  4. customthe residue was purified by preparative thin layer chromatography (0.5 mm×2 plates, hexane

Sources & evidence

ORD record
ord-4a993fa913d6426898c5f265b155dfcd
Source dataset
uspto-grants-2011_07
Patent number
US07985744B2

Reaction notes

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