MAGNESIUM SILICATE (synthetic) → 1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-oxopregna-5,7,16-triene

HRID 1268511Notes

Reaction equation

HRID 1268511 reaction equation
[Si:1]([O:8][C@@H:9]1[C@@:28]2([CH3:29])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:27]2[CH2:26][CH2:25][C@@:24]2([CH3:30])[C@H:17]3[CH2:18][CH:19]=[C:20]2[C@@H:21]([OH:23])[CH3:22])[CH2:12][C@@H:11]([O:31][Si:32]([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:34])[CH3:33])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[O-][Si]([O-])=O.[Mg+2]>ClCCl>[Si:1]([O:8][C@@H:9]1[C@@:28]2([CH3:29])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:27]2[CH2:26][CH2:25][C@@:24]2([CH3:30])[C@H:17]3[CH2:18][CH:19]=[C:20]2[C:21](=[O:23])[CH3:22])[CH2:12][C@@H:11]([O:31][Si:32]([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:33])[CH3:34])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 61680MAGNESIUM SILICATE (synthetic)HCID 2724130Cornforth reagentHCID 120200781alpha,3beta-bis(tert-butyldimethylsilyloxy)-20(S)-hydroxypregna-5,7,16-triene

Product 1

HCID 120200821alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-oxopregna-5,7,16-trieneYield 57.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A suspension of 1α,3β-bis(tert-butyldimethylsilyloxy)-20(S)-hydroxypregna-5,7,16-triene (600 mg, 1.07 mmol), pyridinium dichromate (610 mg, 1.61 mmol) and Florisil (3 g) in dichloromethane (10 ml) was stirred at room temperature for 1.5 hours, then ultrasonicated for 2.5 hours. The solvent was distilled off under reduced pressure and the resulting residue was diluted with diethyl ether and filtered through Celite. The solvent was distilled off under reduced pressure and the resulting residue was purified by column chromatography (hexane:ethyl acetate=15:1) to give the title compound as a colorless solid (343 mg, 57%).

Workup

  1. customultrasonicated for 2.5 hours
  2. distillationThe solvent was distilled off under reduced pressure
  3. additionthe resulting residue was diluted with diethyl ether
  4. filtrationfiltered through Celite
  5. distillationThe solvent was distilled off under reduced pressure
  6. customthe resulting residue was purified by column chromatography (hexane:ethyl acetate=15:1)

Sources & evidence

ORD record
ord-a324d89c92ca449dba05a11298b7f225
Source dataset
uspto-grants-2003_04
Patent number
US06555699B2

Reaction notes

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