Hydrochloric Acid → Cholesta-5,7-diene-3-one

HRID 861810

Reaction equation

HRID 861810 reaction equation
[CH3:1][C@@H:2]([C@@H:9]1[C@@:13]2([CH3:28])[CH2:14][CH2:15][C@@H:16]3[C@@:21]4([CH3:27])[CH2:22][CH2:23][C@H:24]([OH:26])[CH2:25][C:20]4=[CH:19][CH:18]=[C:17]3[C@@H:12]2[CH2:11][CH2:10]1)[CH2:3][CH2:4][CH2:5][CH:6]([CH3:8])[CH3:7].CC(C)[O-].[Al+3].CC(C)[O-].CC(C)[O-].Cl>CC(=O)CC>[CH3:8][CH:6]([CH2:5][CH2:4][CH2:3][C@H:2]([C@@H:9]1[C@:13]2([CH3:28])[C@H:12]([C:17]3[C@H:16]([CH2:15][CH2:14]2)[C@:21]2([CH3:27])[C:20]([CH2:25][C:24](=[O:26])[CH2:23][CH2:22]2)=[CH:19][CH:18]=3)[CH2:11][CH2:10]1)[CH3:1])[CH3:7]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 11143Aluminum isopropoxideHCID 4394237-Dehydrocholesterol

Product 1

HCID 15480063Cholesta-5,7-diene-3-oneYield 103.1%

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

1.15 g of dehydrocholesterol was dissolved in 15 ml of 2-butanone, 0.34 g of aluminum isopropoxide was added, and the mixture was heated at reflux temperature for 75 mutes. After cooling on an ice bath, 15 ml of 2N hydrochloric acid was added, the phases were separated, and the organic phase was washed twice with 7.5 ml of 2N hydrochloric acid. The aqueous phase was extracted with toluene, and the combined organic phases were washed with water and brine, dried, and evaporated to yield 1.18 g of crude cholesta-5,7-diene-3-one as a viscous oil.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux temperature for 75 mutes
  3. temperatureAfter cooling on an ice bath
  4. customthe phases were separated
  5. washthe organic phase was washed twice with 7.5 ml of 2N hydrochloric acid
  6. extractionThe aqueous phase was extracted with toluene
  7. washthe combined organic phases were washed with water and brine
  8. customdried
  9. customevaporated

Sources & evidence

ORD record
ord-9c3d7d2edf9a4f2e830ee5a7679efc00
Source dataset
uspto-grants-1998_02
Patent number
US05716777

Linked notes

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