[OH:1][C:2]([C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[CH2:3][NH:4]C(=O)OCCCC.S(=O)(=O)(O)O.[C:29](=O)(O)[O-].[Na+]>CO>[CH3:29][O:1][C:2]([C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[CH2:3][NH2:4]A solution of tent-butyl 2-hydroxy-2,2-diphenylethylcarbamate (0.42 g, 1.39 mmol) in methanol (10 mL) was treated with concentrated sulfuric acid (2 mL). The reaction was stirred at 23° C. for a week and then at 40° C. for 2 hours. Solid sodium bicarbonate was added to the reaction until the pH reached ˜6-7 and the methanol was evaporated. The residue was then taken into ethyl acetate/water and the aqueous phase was extracted with ethyl acetate (3×). The combined organic layers were dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified on preparative HPLC (ammonium acetate/acetonitrile/water) to give the title material (0.140 g, 46%). 1H NMR (400 MHz, CDCl3) δ: 3.11 (3H, s), 3.54 (2H, br s), 3.98 (2H, br s), 7.24-7.30 (2H, m), 7.31-7.36 (8H, m).
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