Maltol → 3-(3-Hydroxypropoxy)-2-methyl-4H-pyran-4-one

HRID 1647164Notes

Reaction equation

HRID 1647164 reaction equation
[OH:1][C:2]1[C:7](=[O:8])[CH:6]=[CH:5][O:4][C:3]=1[CH3:9].Br[CH2:11][CH2:12][CH2:13][OH:14].C([O-])([O-])=O.[K+].[K+]>CC(C)=O>[OH:14][CH2:13][CH2:12][CH2:11][O:1][C:2]1[C:7](=[O:8])[CH:6]=[CH:5][O:4][C:3]=1[CH3:9]

Participants

5

Reactant 3

HCID 8369MaltolHCID 11430Potassium CarbonateHCID 123083-Bromo-1-propanol

Product 1

HCID 104649893-(3-Hydroxypropoxy)-2-methyl-4H-pyran-4-oneYield 22%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A suspension of 3-hydroxy-2-methyl-4-pyrone (25 g, 200 mmol), 3-bromo-1-propanol (70 g, 500 mmol) and K2CO3 (111 g 800 mmol) in 600 ml acetone was stirred for three days. The solvent was evaporated and the residue partitioned between 300 ml methylene chloride and 500 ml 2.5% NaOH. The aqueous layer was separated and extracted with 2×300 ml methylene chloride. The organic phases were combined, dried over Na2SO4 and evaporated at 50° C. Eight grams of the residue (24 g) was chromatographed on silica gel with methanol/methylene chloride (5:95) as eluent which afforded 2.7 g (22%) of the desired product as an oil.

Workup

  1. customThe solvent was evaporated
  2. customthe residue partitioned between 300 ml methylene chloride and 500 ml 2.5% NaOH
  3. customThe aqueous layer was separated
  4. extractionextracted with 2×300 ml methylene chloride
  5. dry with materialdried over Na2SO4
  6. customevaporated at 50° C
  7. customEight grams of the residue (24 g) was chromatographed on silica gel with methanol/methylene chloride (5:95) as eluent which

Sources & evidence

ORD record
ord-308fdc073d7847f59242fdca963c317b
Source dataset
uspto-grants-1995_07
Patent number
US05430042

Reaction notes

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