[CH3:1][N:2]1[CH2:6][CH2:5][C@H:4]([O:7][C:8]2[CH:9]=[C:10]([CH:15]=[C:16]([O:18][CH2:19][C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)[CH:17]=2)[C:11]([O:13]C)=[O:12])[C:3]1=[O:26].CO.[OH-].[Li+].O>C1COCC1>[CH3:1][N:2]1[CH2:6][CH2:5][C@H:4]([O:7][C:8]2[CH:9]=[C:10]([CH:15]=[C:16]([O:18][CH2:19][C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)[CH:17]=2)[C:11]([OH:13])=[O:12])[C:3]1=[O:26]Methyl 3-[(3S)-1-methyl-2-oxo-pyrrolidin-3-yl]oxy-5-phenylmethoxy-benzoate (Intermediate 9) (2.4 g, 6.8 mmol) was dissolved in THF (45 mL), methanol (15 mL) and 1 N lithiumhydroxide (8.1 mL). Water (60 mL) was added dropwise until the solution went cloudy and the resultant solution was stirred for 3 hours at room temperature. The organics were removed by evaporation under reduced pressure, the aqueous solution was filtered, acidified with 2N hydrochloric acid, extracted with ethyl acetate (3×20 mL), washed with water (10 mL), brine (10 mL) and evaporated to dryness under reduced pressure to give product (2.106 g, 92%). 1H NMR 6 (300 MHz, CDCl3) 2.07-2.21 (m, 1H), 2.51-2.65 (m, 1H), 2.96 (s, 3H), 3.32-3.55 (m, 2H), 4.92 (t, 1H), 5.06 (s, 2H), 6.88 (s, 1H), 7.28-7.46 (m, 7H); m/z 340 (M−H)−.
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