[F:1][C:2]1[CH:3]=[C:4]([CH:17]=[CH:18][CH:19]=1)[CH:5]=[C:6]1[CH2:10][N:9]([C:11]([OH:13])=[O:12])[CH:8]([C:14]([OH:16])=[O:15])[CH2:7]1.O.[OH-].[Li+]>O1CCCC1.O>[C:4]([O:12][C:11]([N:9]1[CH2:10][C:6](=[CH:5][C:4]2[CH:17]=[CH:18][CH:19]=[C:2]([F:1])[CH:3]=2)[CH2:7][CH:8]1[C:14]([OH:16])=[O:15])=[O:13])([CH3:17])([CH3:5])[CH3:3]To a stirred solution of 4-(3-Fluoro-benzylidene)-pyrrolidine-1,2-dicarboxylic acid 1-terf butyl ester 2-methyl ester (3.23 g, 9.63 mmol) in tetrahydrofuran (150 ml), was added 1M lithium hydroxide monohydrate (1.21 g, 28.9 mmol) in water (50 ml). The mixture was stirred at room temperature for 3 days. Tetrahydrofuran was removed by evaporation under reduced pressure, the residue diluted with water (30 ml) and acidified to pH 2.0-3.0 using 1M hydrochloric acid. The aqueous was extracted with diethyl ether (3×100 ml) and the combined organics dried over magnesium sulfate. The solvent was removed by evaporation under reduced pressure to give the title compound (2.37 g, 77%) as a white foam.
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