To a solution of (R)-7-(naphthalene-2-sulfonyl)-7-aza-bicyclo[4.2.1]nonane-8-carboxylic acid ethyl ester (0.55 g, 1.42 mmol) in tetrahydrofuran (15 mL) is added a solution of lithium hydroxide (1.2 g, 28.6 mmol) in water (15 mL). The reaction is heated to 80° C. for 16 h, and the solvent is removed in vacuo. The residue is dissolved in water and washed with diethyl ether. The aqueous layer is then acidified with 6 N hydrochloric acid to pH less than 4 and extracted three times with ethyl acetate. The combined organic extracts are washed with brine, dried over magnesium sulfate, and concentrated to afford the title compound as a yellow solid (0.50 g, 98% yield). LCMS (m/z): 360.07 (M+1), 358.12 (M−1).
