Phosphorus oxychloride → 3-Chlorocholest-5,24-diene

HRID 1448019Notes

Reaction equation

HRID 1448019 reaction equation
O[C@@H:2]1[CH2:27][CH2:26][C@@:25]2([CH3:28])[C@H:4]([C@@H:5](O)[CH2:6][C@@H:7]3[C@@H:24]2[CH2:23][CH2:22][C@@:21]2([CH3:29])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C@H:12]([CH3:20])[CH2:13][CH2:14][CH:15](O)[CH:16]([CH3:18])[CH3:17])[CH2:3]1.P(Cl)(Cl)([Cl:33])=O>N1C=CC=CC=1>[Cl:33][CH:2]1[CH2:27][CH2:26][C@@:25]2([CH3:28])[C:4](=[CH:5][CH2:6][C@@H:7]3[C@@H:24]2[CH2:23][CH2:22][C@@:21]2([CH3:29])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C@H:12]([CH3:20])[CH2:13][CH2:14][CH:15]=[C:16]([CH3:18])[CH3:17])[CH2:3]1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 69762612HCID 69762612, compound

Product 1

HCID 542346983-Chlorocholest-5,24-diene

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To the solution of 3α,6α,24-trihydroxy-5β-cholestan (1.5 g) in pyridine (20 ml) was added phosphorus oxychloride (3 ml). After completion of the reaction, the reaction mixture was poured into ice-water and extracted with diethyl ether. The ether layer was washed with an aqueous solution of hydrochloric acid and then with water, dried over magnesium sulfate and evaporated to dryness. The residue was chromatographed on silica gel to give 0.6 g of 3-chlorocholest-5,24-diene.

Workup

  1. customAfter completion of the reaction
  2. extractionextracted with diethyl ether
  3. washThe ether layer was washed with an aqueous solution of hydrochloric acid
  4. dry with materialwith water, dried over magnesium sulfate
  5. customevaporated to dryness
  6. customThe residue was chromatographed on silica gel

Sources & evidence

ORD record
ord-db7e2fa778ff4955b31b1e6ce355aaa6
Source dataset
uspto-grants-1979_12
Patent number
US04179452

Reaction notes

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