C[O:2][C:3](=[O:25])[CH:4]([C:11]1[CH:16]=[CH:15][C:14]([S:17]([CH3:20])(=[O:19])=[O:18])=[C:13]([C:21]([F:24])([F:23])[F:22])[CH:12]=1)[CH2:5][CH:6]1[CH2:10][CH2:9][CH2:8][CH2:7]1.[OH-].[Li+]>O1CCCC1.O>[CH:6]1([CH2:5][CH:4]([C:11]2[CH:16]=[CH:15][C:14]([S:17]([CH3:20])(=[O:19])=[O:18])=[C:13]([C:21]([F:24])([F:22])[F:23])[CH:12]=2)[C:3]([OH:25])=[O:2])[CH2:10][CH2:9][CH2:8][CH2:7]1A solution of 3-cyclopentyl-2-(4-methanesulfonyl-3-trifluoromethyl-phenyl)-propionic acid methyl ester (prepared as in Example 89A, 2.92 g, 7.72 mmol) in tetrahydrofuran/water (88 mL, 3:1) was treated with lithium hydroxide (647 mg, 15.43 mmol). The reaction was stirred at 25° C. for 3 d. The tetrahydrofuran was then removed in vacuo. The residue was diluted with water (50 mL) and extracted with ether (25 mL). The aqueous layer was acidified to pH=1 with a 3N aqueous hydrochloric acid solution. The product was extracted into ethyl acetate (3×75 mL) and ether (1×50 mL). The combined organic layers were washed with a saturated aqueous sodium chloride solution (2×100 mL), dried over magnesium sulfate and sodium sulfate, filtered, and concentrated in vacuo to give 3-cyclopentyl-2-(4-methanesulfonyl-3-trifluoromethyl-phenyl)-propionic acid (2.37 g, 84.5%) as a pale-yellow semi-solid: EI-HRMS m/e calcd for C16H19F3O4S (M+) 364.0956, found 364.0958.
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