Lithium hydroxide, monohydrate → HCID 66899051, Verbindung

A solution of (S)-2-{4-[4-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-phenoxy]-2-oxo-2,5-dihydro-pyrrol-1-yl}-4-methyl-pentanoic acid methyl ester (0.198 g, 0.47 mmol) in tetrahydrofuran (5 mL) and water (1 mL) was treated with lithium hydroxide monohydrate (0.022 g 0.51 mmol) and stirred at room temperature for 1.5 h. The mixture was partitioned between ethyl acetate and water and the layers separated. The aqueous phase was acidified with 1N aqueous hydrochloric acid (pH=1) and extracted with ethyl acetate. The combined organic layers from extraction of the acidic aqueous layer were dried over sodium sulfate, filtered and concentrated in vacuo. The residue was treated with dichloromethane/hexanes and the precipitate isolated by filtration to afford (S)-2-{4-[4-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-phenoxy]-2-oxo-2,5-dihydro-pyrrol-1-yl}-4-methyl-pentanoic acid (148 mg, 77%), as a white solid.