Acetic Acid → 24-Ketocholesterol

HRID 2397950Notes

Reaction equation

HRID 2397950 reaction equation
C/C=[C:3](/[CH:28]([CH3:30])[CH3:29])\[CH2:4][CH2:5][C@H:6]([C@@H:8]1[C@@:12]2([CH3:27])[CH2:13][CH2:14][C@@H:15]3[C@@:20]4([CH3:26])[CH2:21]C[C@H](O)[CH2:24][C:19]4=[CH:18][CH2:17][C@H:16]3[C@@H:11]2[CH2:10][CH2:9]1)[CH3:7].C(=O)=[O:32].CC(C)=O.O=[O+][O-].O=O.[C:43]([OH:46])(=O)[CH3:44]>[Zn].C(Cl)Cl>[O:32]=[C:3]([CH2:4][CH2:5][C@H:6]([C@@H:8]1[C@:12]2([CH3:27])[C@H:11]([C@H:16]3[C@H:15]([CH2:14][CH2:13]2)[C@:20]2([CH3:21])[C:19]([CH2:24][C@H:43]([CH2:44][CH2:26]2)[OH:46])=[CH:18][CH2:17]3)[CH2:10][CH2:9]1)[CH3:7])[CH:28]([CH3:29])[CH3:30]

Participants

8

Reactant 5

HCID 176Acetic AcidHCID 977OxygenHCID 24823OzoneHCID 5281328Fucosterol2×HCID 18522661Acetone cardice

Product 1

HCID 1103680824-KetocholesterolYield 70.3%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 6344DichloromethaneSolvent

Procedure

Fucosterol (4.1 g) was dissolved in 100 ml. of methylene chloride, and while cooling the solution with dry ice-acetone to about -20° C., the fucosterol was oxidized for 30 minutes with ozone at a rate of generation of 0.86 g/hr and in a concentration of 17.2 g/m3 (O2). After the reaction, 8 g of zinc powder and 200 ml. of acetic acid were added, and the resulting ozonide was reductively decomposed at room temperature for 24 hours. The resulting zinc acetate was separated by filtration, and washed with an aqueous solution of sodium carbonate. The methylene chloride phase separated was thoroughly washed with water, and dried with anhydrous sodium sulfate. The methylene chloride was evaporated off at reduced pressure, and the resulting white crystals were column-chromatographed using silica gel as a carrier (eluted with a benzene-n-hexane mixed solvent) to afford 2.8 g of 24-ketocholesterol in a yield of 70.3%.

Workup

  1. customThe resulting zinc acetate was separated by filtration
  2. washwashed with an aqueous solution of sodium carbonate
  3. customThe methylene chloride phase separated
  4. washwas thoroughly washed with water
  5. dry with materialdried with anhydrous sodium sulfate
  6. customThe methylene chloride was evaporated off at reduced pressure
  7. customthe resulting white crystals were column-chromatographed
  8. washeluted with a benzene-n-hexane mixed solvent)

Sources & evidence

ORD record
ord-b72d0ebee50b49a4b876b81dd2f47932
Source dataset
uspto-grants-1977_05
Patent number
US04022891

Reaction notes

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