Kojic Acid → 5-Hydroxy-2-{[(oxan-2-yl)oxy]methyl}-4H-pyran-4-one

HRID 648764Notes

Reaction equation

HRID 648764 reaction equation
[OH:1][C:2]1[C:3](=[O:10])[CH:4]=[C:5]([CH2:8][OH:9])[O:6][CH:7]=1.[OH2:11].[C:12]1(C)C=[CH:16][C:15](S(O)(=O)=O)=[CH:14][CH:13]=1>C(Cl)Cl>[OH:1][C:2]1[C:3](=[O:10])[CH:4]=[C:5]([CH2:8][O:9][CH:16]2[CH2:15][CH2:14][CH2:13][CH2:12][O:11]2)[O:6][CH:7]=1

Participants

4

Reactant 2

HCID 3840Kojic AcidHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 137117895-Hydroxy-2-{[(oxan-2-yl)oxy]methyl}-4H-pyran-4-oneYield 14,083.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 56.8 g of 5-hydroxy-2-hydroxymethyl-4-pyrone (kojic acid) in 2 L of methylene chloride, 0.4 g of p-toluenesulfonic acid monohydrate was added and the mixture was stirred for 1.5 h. The reaction mixture was extracted with 3% sodium hydroxide solution twice and then the combined aqueous phase was neutralized to pH 8 with 0.5 M sodium dihydrogen phosphate. An extractive work-up (methylene chloride) follwed by recrystallization afforded 67 g (75%) of the title compound (mp 94° C.), NMR (CDCl3) 60 MHz: 4.32 (d, J=14, 1H, right hand of AB pattern), 4.61 (d, J=14, left half of AB pattern), 4.73 (broad S, 1H, acetal H), 6.60 (S, 1H, H-3), 7.86 (S, 1H, H-5) ppm; IR (CHCl3) 3430, 1640, 1600 cm-1 /UV (MeOH): 270 nm (Σ7,400).

Workup

  1. extractionThe reaction mixture was extracted with 3% sodium hydroxide solution twice
  2. customAn extractive work-up (methylene chloride) follwed by recrystallization

Sources & evidence

ORD record
ord-1af8b58ec16b44abaab46763fa5c5358
Source dataset
uspto-grants-1988_04
Patent number
US04735964

Reaction notes

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