Hydrochloric Acid → Desoxycohumulone

HRID 567203Notes

Reaction equation

HRID 567203 reaction equation
[CH3:1][CH:2]([C:4]([C:6]1[C:11]([OH:12])=[CH:10][C:9]([OH:13])=[CH:8][C:7]=1[OH:14])=[O:5])[CH3:3].Br[CH2:16][CH:17]=[C:18]([CH3:20])[CH3:19].Cl>CS(C)=O>[CH3:3][CH:2]([C:4]([C:6]1[C:7]([OH:14])=[C:8]([CH2:16][CH:17]=[C:18]([CH3:20])[CH3:19])[C:9]([OH:13])=[C:10]([CH2:6][CH:4]=[C:2]([CH3:3])[CH3:1])[C:11]=1[OH:12])=[O:5])[CH3:1]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 700922-Butene, 1-bromo-3-methyl-HCID 5326317Phlorisobutyrophenone

Product 1

HCID 25203730DesoxycohumuloneYield 7%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

Under an atmosphere of nitrogen, 600 mg (15.0 mmol, 3.00 equivalents) of an oily 60% sodium hydride was washed with dry hexane to remove paraffin. In this solution, 20 ml of dimethyl sulfoxide was placed and stirred at room temperature. To the resultant mixture, a dimethyl sulfoxide (5.0 ml) solution of 981 mg (5.00 mmol) of (2-propyl) (2,4,6-trihydroxyphenyl) ketone (4) was added over a period of 15 minutes and stirred for 30 minutes. Then, a dimethyl sulfoxide (5.0 ml) solution of 1.43 g (10.0 mmol, 2.00 equivalents) of 1-bromo-3-methyl-2-butene was added dropwise over a period of 30 minutes. The resultant mixture was stirred at room temperature for 14 hours. The mixture was poured into 50 ml of a cold 2 M hydrochloric acid solution and extracted from ether. The ether layer was washed with saturated brine, dried over sodium sulfate, and distilled to remove the solvent and obtain 1.580 g of a crude product in the form of red oily substance. The crude product was separated by silica gel column chromatography (65 g of Wako Gel C-200, benzene:ethyl acetate=9:1) into (a) 239 mg of a brown viscous oily substance, (b) 342 mg of an orange color viscous oily substance, and (c) 206 mg of a yellow crystalline substance sequentially in the order of elution as indexed by the thin layer chromatography. The fraction (a) was further purified by column chromatography (15 g of Wako Gel C-300, petroleum ether:ether=9:1) to obtain 58 mg of {3,5-bis(3-methyl-2-butenyl)-2,4,6-trihydroxyphenyl} (2-propyl) ketone (12) in the form of yellow crystals.

Workup

  1. washUnder an atmosphere of nitrogen, 600 mg (15.0 mmol, 3.00 equivalents) of an oily 60% sodium hydride was washed with dry hexane
  2. customto remove paraffin
  3. stirringstirred for 30 minutes
  4. extractionextracted from ether
  5. washThe ether layer was washed with saturated brine
  6. dry with materialdried over sodium sulfate
  7. distillationdistilled
  8. customto remove the solvent
  9. customobtain 1.580 g of a crude product in the form of red oily substance
  10. customThe crude product was separated by silica gel column chromatography (65 g of Wako Gel C-200, benzene:ethyl acetate=9:1) into (a) 239 mg of a brown viscous oily substance, (b) 342 mg of an orange color viscous oily substance, and (c) 206 mg of a yellow crystalline substance sequentially in the order of elution as indexed by the thin layer chromatography
  11. customThe fraction (a) was further purified by column chromatography (15 g of Wako Gel C-300, petroleum ether:ether=9:1)

Sources & evidence

ORD record
ord-83d81a68594c41e38b740d77f6555f70
Source dataset
uspto-grants-2001_01
Patent number
US06177474B1

Reaction notes

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