Acetone → 5-(benzyloxy)-4-oxo-4H-pyran-2-carboxylic acid

HRID 1252591Notes

Reaction equation

HRID 1252591 reaction equation
[OH:1][CH2:2][C:3]1[O:4][CH:5]=[C:6]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[C:7](=[O:9])[CH:8]=1.CC(C)=[O:20].CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O>O>[O:9]=[C:7]1[C:6]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[CH:5][O:4][C:3]([C:2]([OH:20])=[O:1])=[CH:8]1

Participants

5

Reactant 3

HCID 180AcetoneHCID 9015985-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-oneHCID 131709961Jones' reagent

Product 1

HCID 64807825-(benzyloxy)-4-oxo-4H-pyran-2-carboxylic acidYield 5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

232 g (1 mol) of 2-(hydroxymethyl)-5-(phenylmethoxy)-4H-pyran-4-one were put into a 10 1 stirring flask containing 6.61 of acetone and 400 ml of water. The clear solution was cooled to +5° C. by means of an ice-bath. While maintaining the temperature at +5° to 10° C., 640 ml of Jones Reagent (202 g CrO3, 600 ml water, 174 ml H2SO4) was added dropwise over a period of 1 hr. Stirring was continued for 2 hours without cooling. The reaction mixture was filtered through a glass frit and the dark-green residue washed with 500 ml of acetone. The filtrate was then evaporated until all of the acetone was removed. To the aqueous, partly crystalline product was added 1.2 1 of methanol, and this mixture was then heated to its boiling point. The resulting clear dark-green solution was placed in an ice-bath and the product allowed to crystallize. The crystalline product was filtered and washed with 500 ml of a cold solvent mixture consisting of 250 ml methanol +250 ml water and finally dried. Yield: 195 g=79%. From the mother liquor a further 5% of the product could be isolated.

Workup

  1. temperatureThe clear solution was cooled to +5° C. by means of an ice-bath
  2. temperatureWhile maintaining the temperature at +5° to 10° C.
  3. temperaturewithout cooling
  4. filtrationThe reaction mixture was filtered through a glass frit
  5. washthe dark-green residue washed with 500 ml of acetone
  6. customThe filtrate was then evaporated until all of the acetone
  7. customwas removed
  8. additionTo the aqueous, partly crystalline product was added 1.2 1 of methanol
  9. temperaturethis mixture was then heated to its boiling point
  10. customThe resulting clear dark-green solution was placed in an ice-bath
  11. customto crystallize
  12. filtrationThe crystalline product was filtered
  13. washwashed with 500 ml of a cold solvent mixture
  14. customfinally dried

Sources & evidence

ORD record
ord-c82677a123794a7192e33896e9aec072
Source dataset
uspto-grants-1988_05
Patent number
US04743685

Reaction notes

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