Allyl bromide → 7-Allyloxy-5-hydroxy-2,2-dimethyl-4-oxochromane

HRID 494957Notes

Reaction equation

HRID 494957 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]([OH:12])[CH:9]=[C:8]2[C:3]=1[C:4](=[O:15])[CH2:5][C:6]([CH3:14])([CH3:13])[O:7]2.C(=O)([O-])[O-].[K+].[K+].[CH2:22](Br)[CH:23]=[CH2:24]>CC(C)=O>[CH2:24]([O:12][C:10]1[CH:9]=[C:8]2[C:3]([C:4](=[O:15])[CH2:5][C:6]([CH3:13])([CH3:14])[O:7]2)=[C:2]([OH:1])[CH:11]=1)[CH:23]=[CH2:22]

Participants

5

Reactant 3

HCID 7841Allyl bromide4×HCID 11430Potassium Carbonate4×HCID 8213625,7-Dihydroxy-2,2-dimethylchroman-4-one

Product 1

HCID 576828337-Allyloxy-5-hydroxy-2,2-dimethyl-4-oxochromaneYield 86.5%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

2.81 g of 5,7-dihydroxy-2,2-dimethyl-4-oxochromane was dissolved in 60 ml of acetone. Thereafter, 2.05 g of potassium carbonate and 1.80 g of allyl bromide were added to the reaction solution, and the obtained mixture was then stirred at room temperature for 24 hours. Thereafter, 0.20 g of potassium carbonate and 0.18 g of allyl bromide were further added to the reaction solution, and the obtained mixture was then stirred at room temperature for 10 hours. Thereafter, 0.20 g of potassium carbonate and 0.18 g of allyl bromide were further added to the reaction solution, and the obtained mixture was then stirred at room temperature for 14 hours. Thereafter, 0.20 g of potassium carbonate and 0.18 g of allyl bromide were further added to the reaction solution, and the obtained mixture was then stirred at room temperature for 7 hours. The reaction solution was concentrated under a reduced pressure, and the residue was diluted with ethyl acetate. The resultant product was washed with water and a saturated sodium chloride aqueous solution. The organic layer was dried over magnesium sulfate and then concentrated under a reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate), so as to obtain 2.90 g of the subject compound.

Workup

  1. stirringthe obtained mixture was then stirred at room temperature for 10 hours
  2. stirringthe obtained mixture was then stirred at room temperature for 14 hours
  3. stirringthe obtained mixture was then stirred at room temperature for 7 hours
  4. concentrationThe reaction solution was concentrated under a reduced pressure
  5. additionthe residue was diluted with ethyl acetate
  6. washThe resultant product was washed with water
  7. dry with materialThe organic layer was dried over magnesium sulfate
  8. concentrationconcentrated under a reduced pressure
  9. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate)

Sources & evidence

ORD record
ord-c7999aea152644caa9e29bc854c35291
Source dataset
uspto-grants-2009_05
Patent number
US07538123B2

Reaction notes

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