1-Chloro-3-methyl-2-butene → Deoxyhumulone

HRID 567205Notes

Reaction equation

HRID 567205 reaction equation
[OH:1][C:2]1[CH:7]=[C:6]([OH:8])[CH:5]=[C:4]([OH:9])[C:3]=1[C:10]([CH2:12][CH:13]([CH3:15])[CH3:14])=[O:11].Cl[CH2:17][CH:18]=[C:19]([CH3:21])[CH3:20].[Cl-].[NH4+]>CO>[CH3:14][CH:13]([CH3:15])[CH2:12][C:10]([C:3]1[C:2]([OH:1])=[C:7]([CH2:17][CH:18]=[C:19]([CH3:21])[CH3:20])[C:6]([OH:8])=[C:5]([CH2:7][CH:2]=[C:3]([CH3:10])[CH3:4])[C:4]=1[OH:9])=[O:11]

Participants

5

Reactant 3

HCID 104291-Chloro-3-methyl-2-buteneHCID 25517Ammonium ChlorideHCID 441269phlorisovalerophenone

Product 1

HCID 6450808DeoxyhumuloneYield 17.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

Under an atmosphere of nitrogen, 441 mg (11.1 mmol, 2.06 equivalents) of an oily 60% sodium hydride was washed with dry hexane to remove paraffin. To this was added 6.0 ml of dry methanol cooling with ice and stirred. Then, a methanol (6.0 ml) solution of 1.135 g (5.400 mmol) of (2-methylpropyl) (2,4,6-trihydroxyphenyl) ketone (5) was added dropwise to the solution. Further, a methanol (5.0 ml) solution of 1.205 g (11.52 mmol, 2.130 equivalents) of 1-chloro-3-methyl-2-butene was slowly added dropwise. The mixture was stirred cooling with ice for 1.5 hours, then added 50 ml of a saturated aqueous ammonium chloride solution, and extracted from ether. The ether layer was washed with saturated brine, dried over sodium sulfate, and distilled under a reduced pressure to remove the solvent and obtain 1.752 g of a crude product in the form of a red viscous oily substance. This crude product was subjected to silica gel column chromatography (40 g of Wako Gel C-300 and eluted sequentially with 200 ml each of petroleum ether:ether at varying ratios=19:1, 18:2, 17:3, and 16:4). From the eluate of the column, various fractions were sequentially obtained. As the first fraction, 160 mg of {3,5-bis(3-methyl-2-butenyl)-2,4,6-trihydroxyphenyl} (2-methylpropyl) ketone (15) was obtained in the form of light yellow crystals shaped fine needles.

Workup

  1. washUnder an atmosphere of nitrogen, 441 mg (11.1 mmol, 2.06 equivalents) of an oily 60% sodium hydride was washed with dry hexane
  2. customto remove paraffin
  3. additionTo this was added 6.0 ml of dry methanol cooling with ice
  4. stirringThe mixture was stirred
  5. temperaturecooling with ice for 1.5 hours
  6. extractionextracted from ether
  7. washThe ether layer was washed with saturated brine
  8. dry with materialdried over sodium sulfate
  9. distillationdistilled under a reduced pressure
  10. customto remove the solvent
  11. customobtain 1.752 g of a crude product in the form of a red viscous oily substance
  12. washand eluted sequentially with 200 ml each of petroleum ether
  13. customFrom the eluate of the column, various fractions were sequentially obtained

Sources & evidence

ORD record
ord-48ced1de585f41f39ccafe16098041c9
Source dataset
uspto-grants-2001_01
Patent number
US06177474B1

Reaction notes

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