Kojic Acid → 5-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-one

HRID 571036Notes

Reaction equation

HRID 571036 reaction equation
[CH:1]1[C:6](=[O:7])[C:5]([OH:8])=[CH:4][O:3][C:2]=1[CH2:9][OH:10].[OH-].[Na+].[CH2:13](Cl)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>CO.O>[CH2:13]([O:8][C:5]1[C:6](=[O:7])[CH:1]=[C:2]([CH2:9][OH:10])[O:3][CH:4]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 3

HCID 3840Kojic AcidHCID 7503Benzyl ChlorideHCID 14798Sodium Hydroxide

Product 1

HCID 9015985-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-one

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a stirred solution of kojic acid (71.05 g, 0.5 mmol) and sodium hydroxide (22 g, 0.55 mol) in 750 mL of MeOH and 75 mL of water was added benzylchloride (73 g, 0.575 mmol) drop-wise. The resulting mixture was heated at reflux for 4.5 h with stirring. The mixture was then allowed to cool and concentrated to half of the starting volume. The mixture was poured into water, the resultant solid was collected, washed with water, and dried to give 110 g crude compound. The crude compound was re-crystallized from EtOAc to give 5-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-one. 1H NMR 6 (400 MHz, d6-DMSO): 8.14 (s, 1H), 7.40-7.30 (m, 5H), 6.29(s, 1H), 5.68 (t, J=6.0 Hz, 1H), 4.91 (s, 2H), 4.26 (d, J=6.0 Hz,1H).

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureat reflux for 4.5 h
  3. temperatureto cool
  4. concentrationconcentrated to half of the starting volume
  5. additionThe mixture was poured into water
  6. customthe resultant solid was collected
  7. washwashed with water
  8. customdried
  9. customto give 110 g crude compound
  10. customThe crude compound was re-crystallized from EtOAc

Sources & evidence

ORD record
ord-772708f4303841e8ac94020346d9603e
Source dataset
uspto-grants-2015_05
Patent number
US09024032B2

Reaction notes

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