Tetrahydrofuran → 1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-methyleneandrost-5-ene

HRID 1792221Notes

Reaction equation

HRID 1792221 reaction equation
O1CCC[CH2:2]1.CC(C)([O-])C.[K+].[Si:12]([O:19][C@@H:20]1[C@@:37]2([CH3:38])[C:24](=[CH:25][CH2:26][C@@H:27]3[C@@H:36]2[CH2:35][CH2:34][C@@:32]2([CH3:33])[C@H:28]3[CH2:29][CH2:30][CH2:31]2)[CH2:23][C@@H:22]([O:39][Si:40]([C:43]([CH3:46])([CH3:45])[CH3:44])([CH3:42])[CH3:41])[CH2:21]1)([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.CC(C)=O.CO.CCCCCC.O>[Si:12]([O:19][C@@H:20]1[C@@:37]2([CH3:38])[C:24](=[CH:25][CH2:26][C@@H:27]3[C@@H:36]2[CH2:35][CH2:34][C@@:32]2([CH3:33])[C@H:28]3[CH2:29][CH2:30][C:31]2=[CH2:2])[CH2:23][C@@H:22]([O:39][Si:40]([C:43]([CH3:46])([CH3:45])[CH3:44])([CH3:41])[CH3:42])[CH2:21]1)([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13]

Participants

9

Reactant 3

HCID 8028Tetrahydrofuran2×HCID 23665647Potassium tert-butoxideHCID 696305411alpha,3beta-Bis(tert-butyldimethylsilyloxy)androst-5-ene

Product 1

HCID 696308851alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-methyleneandrost-5-ene

Reagents, catalysts & solvents 5

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 180AcetoneSolventHCID 887MethanolSolventHCID 962WaterSolventHCID 8058HexaneSolvent2×

Conditions

Temperature
60 °C

Procedure

A mixture of tetrahydrofuran (70 ml), methyltriphenylphosphonium bromide (50 g) and potassium t-butoxide (13.9 g) were stirred at 60° C. for 2 hours, while under suspension. To this suspension, was added 1α,3β-bis(tert-butyldimethylsilyloxy)androst-5-ene (18.7 g) and tetrahydrofuran (60 ml), followed by reaction for 2 hours under reflux. Under cooling with ice, the reaction mixture was slowly added to a cooled mixture of hexane (200 ml) and water (100 ml) to stop the reaction. The organic layer was washed with saturated brine twice, dried over anhydrous magnesium sulfate and evaporated under reduced pressure to remove the solvent, giving crude crystals (27 g). The crude crystals were mixed with hexane (100 ml), stirred at room temperature while under suspension. After filtering off insoluble material from the suspension, the filtrate was evaporated under reduced pressure to remove the solvent, giving crude crystals, which were then dissolved in acetone (80 ml) by stirring at room temperature. The mixture was mixed with methanol (160 ml) and stirred at room temperature; the thus precipitated crystals were collected by filtration and dried to give the titled compound (13.2 g).

Workup

  1. customfollowed by reaction for 2 hours
  2. temperatureunder reflux
  3. temperatureUnder cooling with ice
  4. customthe reaction
  5. washThe organic layer was washed with saturated brine twice
  6. dry with materialdried over anhydrous magnesium sulfate
  7. customevaporated under reduced pressure
  8. customto remove the solvent
  9. customgiving crude crystals (27 g)
  10. stirringstirred at room temperature while under suspension
  11. filtrationAfter filtering off insoluble material from the suspension
  12. customthe filtrate was evaporated under reduced pressure
  13. customto remove the solvent
  14. customgiving crude crystals, which
  15. stirringby stirring at room temperature
  16. stirringstirred at room temperature
  17. filtrationthe thus precipitated crystals were collected by filtration
  18. customdried

Sources & evidence

ORD record
ord-cf7db74464e144219f9c73c4d6f70138
Source dataset
uspto-grants-2006_07
Patent number
US07074777B2

Reaction notes

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