21-Bromo-3alpha-hydroxy-5alpha-pregnane-11,20-dione → 21-Bromo-5alpha-pregnane-3,11,20-trione

HRID 1576793Notes

Reaction equation

HRID 1576793 reaction equation
[Br:1][CH2:2][C:3](=[O:25])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([C:19](=[O:23])[CH2:20]2)[C@:16]2([CH3:17])[C@H:11]([CH2:12][C@H:13]([OH:24])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1.CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O>CC(C)=O>[Br:1][CH2:2][C:3](=[O:25])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([C:19](=[O:23])[CH2:20]2)[C@:16]2([CH3:17])[C@H:11]([CH2:12][C:13](=[O:24])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1

Participants

4

Reactant 2

HCID 8673346721-Bromo-3alpha-hydroxy-5alpha-pregnane-11,20-dioneHCID 131709961Jones' reagent

Product 1

HCID 8673347421-Bromo-5alpha-pregnane-3,11,20-trioneYield 85.4%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

21-Bromo-3α-hydroxy-5α-pregnane-11,20-dione (412 mg) in acetone (20 ml) was stirred during dropwise addition of Jones reagent (0.4 ml) at room temperature. After 10 minutes, the reaction mixture was poured onto water extracted with chloroform and the combined chloroform extract was washed with water dried (MgSO4) and evaporated. The residue was crystallised from ether/petrol to give title compound (350 mg) as white microcrystals mp 170° [αD ] + 132° (ε 1.1).

Workup

  1. additionthe reaction mixture was poured onto water
  2. extractionextracted with chloroform
  3. extractionthe combined chloroform extract
  4. washwas washed with water
  5. dry with materialdried (MgSO4)
  6. customevaporated
  7. customThe residue was crystallised from ether/petrol

Sources & evidence

ORD record
ord-771fda40cb2e4ae2ab743b6066e8bbbe
Source dataset
uspto-grants-1976_09
Patent number
US03983111

Reaction notes

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