To a solution (S)-ethyl 2-tert-butoxy-2-(1-(4-chlorophenyl)-3-vinylnaphthalen-2-yl)acetate (7.4 mg, 0.0175 mmol) in THF/MeOH (1/1, 1 mL), was added NaOH (2 N, 280 L). The reaction mixture was stirred at room temperature overnight. Then the temperature was raised to 40° C. and the reaction mixture was stirred for 4 h. The reaction was then cooled down and neutralized by adding HOAc. The reaction mixture was concentrated in vacuo and the residue was purified by reverse phase HPLC (Gemini, 5 to 100% ACN/H2O+0.1% TFA) to provide 5.3 mg of the desired product. 1H-NMR: 400 MHz, (CD3OD) δ: 8.07 (s, 1H), 7.89 (d, J=4.0 Hz, 1H), 7.60-7.54 (m, 4H), 7.48-7.44 (m, 1H), 7.35-7.31 (m, 2H), 7.25-7.22 (m, 1H), 5.76-5.71 (m, 1H), 5.29-5.26 (m, 1H), 5.21 (s, 1H), 0.98 (s, 9H). LCMS-ESI− (m/z): [M−H]− calcd for C24H23ClO3: 393.1. Found: 393.0.
