Lithium Hydroxide → 1-[(Benzyloxy)carbonyl]-3-methylpiperidine-3-carboxylic acid

To 1-benzyl 3-ethyl 3-methylpiperidine-1,3-dicarboxylate (3.0 g, 10.0 mmol) in ethanol (15 mL) was added LiOH (15.0 mL, 30.1 mmol), and the reaction mixture was stirred at 86° C. for 1 hour. The ethanol was removed, and ether (30 mL) was added. The aqueous layer was separated and acidified with saturated potassium hydrogen sulfate to a pH of about 3 to about 4, extracted with ethyl acetate (50 mL), and washed with brine and dried over sodium sulfate. After removal of the solvent, 1-(benzyloxycarbonyl)-3-methylpiperidine-3-carboxylic acid (2.6 g, 92% yield) was isolated as an oil.