Oxane-4-carboxylic acid → 2H-Pyran-4-carboxylic acid, tetrahydro-, methyl ester

HRID 1408692Notes

Reaction equation

HRID 1408692 reaction equation
[O:1]1[CH2:6][CH2:5][CH:4]([C:7]([OH:9])=[O:8])[CH2:3][CH2:2]1.O.[CH3:11]C1C=CC(S(O)(=O)=O)=CC=1>CO>[O:1]1[CH2:6][CH2:5][CH:4]([C:7]([O:9][CH3:11])=[O:8])[CH2:3][CH2:2]1

Participants

4

Reactant 2

HCID 219302Oxane-4-carboxylic acidHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 27735202H-Pyran-4-carboxylic acid, tetrahydro-, methyl esterYield 75%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of tetrahydro-2H-pyran-4-carboxylic acid (50 g, 385 mmol) in anhydrous methanol (500 mL) was added 4-methylbenzenesulfonic acid hydrate (72.5 g, 385 mmol). The mixture was refluxed for 2 hr. The solvent was removed in vacuo. Ethyl ether and water was added. The organic phase was washed with water and brine, then dried over Na2SO4, filtered and concentrated to give methyl tetrahydro-2H-pyran-4-carboxylate (8.3 g, 75%), which was used in next step without purification.

Workup

  1. temperatureThe mixture was refluxed for 2 hr
  2. customThe solvent was removed in vacuo
  3. additionEthyl ether and water was added
  4. washThe organic phase was washed with water and brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-5d9ac6331b1e488fa94774ae369b93bd
Source dataset
uspto-grants-2014_12
Patent number
US08921359B2

Reaction notes

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