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

HRID 1792169Notes

Reaction equation

HRID 1792169 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), was added N-bromosuccinimide (65.1 mg, 0.366 mmol) at 0° C., followed by stirring at room temperature. After 1 hour, hexane was added to the mixture and washed with water and then saturated brine. The organic layer was dried over anhydrous magnesium sulfate and evaporated under reduced pressure to remove the solvent, giving a mixture (150 mg) containing 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(bromomethyl)androsta-5,7,16-triene. The mixture was dissolved in acetone (1.5 ml), to which potassium thioacetate (31.4 mg, 0.275 mmol) was added, followed by stirring for 30 min. The reaction mixture was diluted with hexane, filtered and the resulting filtrate was evaporated under reduced pressure to remove the solvent. The residue was purified by preparative thin layer chromatography (2 sheets (each 0.5 mm thickness), hexane:ethyl acetate=20:1, developed once) to give the titled compound (70.2 mg, 64%) as a colorless oil.

Workup

  1. additionwas added
  2. filtrationfiltered
  3. customthe resulting filtrate was evaporated under reduced pressure
  4. customto remove the solvent
  5. customThe residue was purified by preparative thin layer chromatography (2 sheets (each 0.5 mm thickness), hexane

Sources & evidence

ORD record
ord-068d92d58af1432dad376d55043050cc
Source dataset
uspto-grants-2006_07
Patent number
US07074777B2

Reaction notes

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