[C:1]([O:4][CH:5]1[CH:9]([N:10]2[C:14]3[CH:15]=[C:16]([Cl:20])[C:17]([Cl:19])=[CH:18][C:13]=3[N:12]=[CH:11]2)[CH2:8][CH:7]([CH2:21][O:22][C:23](=[O:25])[CH3:24])[CH:6]1[O:26][C:27](=[O:29])[CH3:28])(=[O:3])[CH3:2].[Cl:30]N1C(=O)CCC1=O>CN(C)C=O>[C:1]([O:4][CH:5]1[CH:9]([N:10]2[C:14]3[CH:15]=[C:16]([Cl:20])[C:17]([Cl:19])=[CH:18][C:13]=3[N:12]=[C:11]2[Cl:30])[CH2:8][CH:7]([CH2:21][O:22][C:23](=[O:25])[CH3:24])[CH:6]1[O:26][C:27](=[O:29])[CH3:28])(=[O:3])[CH3:2](±)-(1R*, 2S*, 3S*, 5S*)-3-(Acetoxymethyl)-5-(5,6-dichloro-1H-benzimidazol-1-yl)-1,2-cyclopentanediyl diacetate (850 mg, 1.92 mmol) in dry N,N-dimethylformamide (5 mL) was maintained at 95° C. while N-chlorosuccinimide (760 mg) was added in portions over 3 hours. Heating was continued for a total of 6 hours. Volatiles were removed in vacuo and the residue chromatographed on silica gel. Title compound was eluted with ethyl acetate:hexanes/3:7 as a yellow solid (160 mg, 17%), 1H-NMR consistent with structure and almost identical with that of title compound of Example 3.
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