Benzyl Bromide → 3-Benzyloxy-2-methyl-4-pyrone

HRID 350646Notes

Reaction equation

HRID 350646 reaction equation
[OH:1][C:2]1[C:7](=[O:8])[CH:6]=[CH:5][O:4][C:3]=1[CH3:9].[H-].[Na+].[CH2:12](Br)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>CN(C=O)C>[CH2:12]([O:1][C:2]1[C:7](=[O:8])[CH:6]=[CH:5][O:4][C:3]=1[CH3:9])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 8369MaltolHCID 24758Sodium hydride

Product 1

HCID 14901193-Benzyloxy-2-methyl-4-pyroneYield 97.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

3-Hydroxy-2-methyl-4-pyrone (25 g, 0.198 mol) was dissolved in 70 ml of DMF. To the solution was added 8.7 g (0.218 mol) of sodium hydride (60% in mineral oil). The mixture was stirred under ice cooling for 30 min. Benzyl bromide (37.3 g, 0.218 mol) was added dropwise to the reaction solution under ice cooling, and a reaction was allowed to proceed at room temperature overnight. The reaction solution was poured into ice water, followed by extraction with ethyl acetate. The organic layer was washed with water, and was dried over anhydrous sodium sulfate. The solvent was removed by distillation under the reduced pressure. The reddish brown oil thus obtained (64 g) was applied to column chromatography on silica gel (Wako Gel C-200, n-hexane-ethyl acetate) to give 41.6 g (yield 97%) of 3-benzyloxy-2-methyl-4-pyrone.

Workup

  1. waitto proceed at room temperature overnight
  2. extractionfollowed by extraction with ethyl acetate
  3. washThe organic layer was washed with water
  4. dry with materialwas dried over anhydrous sodium sulfate
  5. customThe solvent was removed by distillation under the reduced pressure
  6. customThe reddish brown oil thus obtained (64 g)

Sources & evidence

ORD record
ord-d9b40923968e4988b6bac9cff74d712e
Source dataset
uspto-grants-2007_02
Patent number
US07183278B1

Reaction notes

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