Sodium hydride → 1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(tert-butoxycarbonylmethoxymethyl)androsta-5,7,16-triene

HRID 1014975Notes

Reaction equation

HRID 1014975 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][OH:29])[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].[H-].[Na+].C1OCCOCCOCCOCCOC1.Br[CH2:56][C:57]([O:59][C:60]([CH3:63])([CH3:62])[CH3:61])=[O:58]>O1CCCC1.C(OCC)(=O)C>[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][O:29][CH2:56][C:57]([O:59][C:60]([CH3:63])([CH3:62])[CH3:61])=[O:58])[CH2:12][C@@H:11]([O:30][Si:31]([C:34]([CH3:37])([CH3:36])[CH3:35])([CH3:32])[CH3:33])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

7

Reactant 4

HCID 24758Sodium hydrideHCID 3633615-Crown-5HCID 79177tert-Butyl bromoacetateHCID 673014381alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(hydroxymethyl)androsta-5,7,16-triene

Product 1

HCID 673017221alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(tert-butoxycarbonylmethoxymethyl)androsta-5,7,16-trieneYield 78.1%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(hydroxymethyl)androsta-5,7,16-triene (1.0 g, 1.84 mmol), sodium hydride (60% in oil, 220 mg, 5.50 mmol), 15-crown-5 (400 mg, 1.82 mmol) and t-butyl bromoacetate (0.55 ml, 3.69 mmol) in tetrahydrofuran (20 ml) was stirred at an external temperature of 88° C. for 1 hour and 15 minutes. The reaction mixture was diluted with ethyl acetate and filtered through CELITE. Water was added dropwise to the filtrate under ice cooling, followed by washing with saturated aqueous sodium chloride. The organic layer was dried over anhydrous magnesium sulfate. After evaporation under reduced pressure to remove the solvent, the resulting residue was purified by column chromatography (hexane:ethyl acetate=20:1) to give the titled compound (946.6 mg, 78%) as a colorless oil.

Workup

  1. filtrationfiltered through CELITE
  2. additionWater was added dropwise to the filtrate under ice cooling
  3. washby washing with saturated aqueous sodium chloride
  4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  5. customAfter evaporation under reduced pressure
  6. customto remove the solvent
  7. customthe resulting residue was purified by column chromatography (hexane:ethyl acetate=20:1)

Sources & evidence

ORD record
ord-206bbaf571c346fabcd05a38ec7bbb12
Source dataset
uspto-grants-2011_07
Patent number
US07985744B2

Reaction notes

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