General procedure for the synthesis of 2-methoxy-2-methylpropionic acid from methyl 2-methoxy-2-methylpropionate: Methyl 2-methoxy-2-methylpropionate (2.08 g, 15.74 mmol) was dissolved in methanol (20 mL), and aqueous (10 mL) solution of potassium hydroxide (1.766 g, 31.5 mmol) was added, and the reaction was stirred for 4 h at room temperature. Upon completion of the reaction, the organic solvent was removed by distillation under reduced pressure and the remaining aqueous phase was washed with a 1:1 hexahydronaphthalene/ether mixture and subsequently acidified with 3N hydrochloric acid. The acidified aqueous phase was extracted with dichloromethane (3×20 mL), and the organic phases were combined and dried with anhydrous sodium sulfate. The dried organic phase was concentrated to dryness under reduced pressure to afford 2-methoxy-2-methylpropionic acid (1.24 g, 67% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 12.48 (s, 1H), 3.12 (s, 3H), 1.27 (s, 6H).
