Cholesterol → 5alpha,6alpha-Epoxycholesterol

HRID 980788Notes

Reaction equation

HRID 980788 reaction equation
[CH3:1][CH:2]([CH2:4][CH2:5][CH2:6][C@H:7]([C@@H:9]1[C@:27]2([CH3:28])[C@H:12]([C@H:13]3[C@H:24]([CH2:25][CH2:26]2)[C@:22]2([CH3:23])[C:16]([CH2:17][C@H:18]([CH2:20][CH2:21]2)[OH:19])=[CH:15][CH2:14]3)[CH2:11][CH2:10]1)[CH3:8])[CH3:3].ClC1C=CC=C(C(OO)=[O:37])C=1>C(Cl)Cl>[CH3:8][C@@H:7]([C@@H:9]1[C@@:27]2([CH3:28])[CH2:26][CH2:25][C@@H:24]3[C@@:22]4([CH3:23])[CH2:21][CH2:20][C@H:18]([OH:19])[CH2:17][C@:16]54[O:37][C@H:15]5[CH2:14][C@H:13]3[C@@H:12]2[CH2:11][CH2:10]1)[CH2:6][CH2:5][CH2:4][CH:2]([CH3:1])[CH3:3]

Participants

4

Reactant 2

HCID 5997Cholesterol2×HCID 70297m-Chloroperbenzoic acid

Product 1

HCID 2270375alpha,6alpha-Epoxycholesterol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Pure cholesterol epoxides are not generally available from commercial sources, so they were synthesized from cholesterol. Analytical grade cholesterol, purified through the dibromide, was employed in these syntheses. Cholesterol 5α,6α-epoxide was synthesized by the procedure of Fieser, L. F. and Fieser, M., in "Reagents for Organic Synthesis," Vol. 1, 1967 John Wiley, New York, p. 136. Cholesterol (50 mmol) in methylene chloride (75 ml) solution was treated at 25° C. over a 30 minute interval with m-chloroperbenzoic acid (54 mmol) in methylene chloride (120 ml) solution. Excess peracid was destroyed by the addition of 10% sodium sulfite. Extraction of the organic layer with 5% aqueous sodium bicarbonate, water, and finally with saturated aqueous sodium chloride, followed by drying and evaporation produced a crude product readily purified by recrystallization from 88% aqueous acetone or by silica gel chromatography. Cholesterol 5α,6α-epoxide (>95% purity, m.p. 142°-143°) was obtained in >90% yield.

Workup

  1. customAnalytical grade cholesterol, purified through the dibromide
  2. custom, in "Reagents for Organic Synthesis," Vol. 1, 1967 John Wiley, New York, p
  3. customExcess peracid was destroyed by the addition of 10% sodium sulfite
  4. extractionExtraction of the organic layer with 5% aqueous sodium bicarbonate, water
  5. customby drying
  6. customevaporation
  7. customproduced a crude product

Sources & evidence

ORD record
ord-8b484693361e49c8aa357720762ab530
Source dataset
uspto-grants-1987_01
Patent number
US04639420

Reaction notes

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