General procedure for the synthesis of 4-hydroxycyclohexylacetic acid from methyl (4-hydroxycyclohexyl)acetate: potassium hydroxide (326 mg) and methyl 2-(4-hydroxycyclohexyl)acetate (500 mg) were dissolved in a mixed solvent of methanol (20 mL) and water (20 mL), and the reaction was stirred for 6 hours at 60 °C. After completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure to remove most of the solvent. Subsequently, the pH was adjusted to 1 with 2 M hydrochloric acid solution, followed by extraction with ethyl acetate (50 mL). The organic layer was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 4-hydroxycyclohexylacetic acid (150 mg) as a white solid. Mass spectrometry (ESI) analysis showed that the theoretical molecular weight of C8H14O3 was 158 and the measured value was 159 [M+H]+.
