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

HRID 2304203Notes

Reaction equation

HRID 2304203 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-1d8044be802642ff976858d8c359673a
Source dataset
uspto-grants-2002_08
Patent number
US06433200B1

Reaction notes

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