Methanol → Methyl 2-ethyl-2-hydroxybutanoate

To a solution of 2-ethyl-2-hydroxybutyric acid (5.00 g) in methanol (35 mL) was added conc. sulfuric acid (0.25 mL), and the mixture was refluxed at room temperature for 18 hours and then refluxed under heating for 18 hours. After cooling, the reaction mixture was concentrated in vacuo, and the resultant residue was diluted with diethylether. The mixture was washed successively with an aqueous saturated sodium hydrogencarbonate solution and brine, dried over sodium sulfate and concentrated in vacuo. The residue was distilled to give methyl 2-ethyl-2-hydroxybutyrate (3.70 g) as a colorless oil.