[C:1]1([C:7]23[CH2:14][N:13]([C:15]([O:17][CH2:18][C:19]4[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=4)=[O:16])[CH2:12][CH:11]2[CH2:10][O:9][NH:8]3)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C(OCC)(=O)C>C(O)(=O)C.[Zn]>[NH2:8][C:7]1([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[CH:11]([CH2:10][OH:9])[CH2:12][N:13]([C:15]([O:17][CH2:18][C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)=[O:16])[CH2:14]1Powdered zinc (43.7 g, 669 mmol) is added to a solution of benzyl 6a-phenyl-3,3a,4,6-tetrahydro-1H-pyrrolo[3,4-c]isoxazole-5-carboxylate (31 g, 96 mmol) in acetic acid (310 mL) and the mixture is stirred for 30 minutes. Ethyl acetate (500 mL) is added and the mixture is filtered through diatomaceous earth. The solvent is removed under vacuum and the crude product is re-dissolved in ethyl acetate. Water is added to the solution and the pH is adjusted to 10 with 2 M NaOH. The solution is filtered through diatomaceous earth, the layers are separated, and the organic layer is dried over magnesium sulfate, and concentrated to give the title compound (31 g, 99%). ES/MS (m/e): 327 (M+H).
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