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

Participants

Reaction Steps

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.

Provenance & Evidence