[CH3:1][O:2][C:3](=[O:21])[CH2:4][C:5]12[CH2:13][CH2:12][C:8]([C:14]3[CH:19]=[CH:18][C:17]([Cl:20])=[CH:16][CH:15]=3)([CH:9](Br)[CH2:10]1)[O:7][CH2:6]2.[BH4-].[Na+]>CO.C(OCC)(=O)C.O1CCCC1.ClC1C=CC=CC=1.[Ni](Cl)Cl>[CH3:1][O:2][C:3](=[O:21])[CH2:4][C:5]12[CH2:13][CH2:12][C:8]([C:14]3[CH:15]=[CH:16][C:17]([Cl:20])=[CH:18][CH:19]=3)([CH2:9][CH2:10]1)[O:7][CH2:6]2
To a stirred solution of [6-bromo-1-(4-chloro-phenyl)-2-oxa-bicyclo[2.2.2]oct-4-yl]-acetic acid methyl ester (0.75 g, 2.007 mmol) and nickel (II) chloride (0.182 g, 1.405 mmol) in methanol (30 ml), ethyl acetate (15 ml), tetrahydrofuran (15 ml) and chlorobenzene (2 ml) at −30° C., was added carefully sodium borohydride (0.228 g, 6.02 mmol). The reaction mixture was allowed to warm to room temperature for 40 minutes. The solvent was removed under vacuum at room temperature and then water (20 ml) and EtOAc (100 ml) were added. The organic phase was separated and washed with brine, dried over Na2SO4 and concentrated. The residue was purified by flash chromatography (heptanes/acetone 2/1) to afford [1-(4-chloro-phenyl)-2-oxa-bicyclo[2.2.2]oct-4-yl]-acetic acid methyl ester (0.39 g, 66%) as white solid. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.65-1.81 (m, 4H) 1.96 (t, J=8.00 Hz, 4H) 2.11 (s, 2H) 3.62 (s, 3H) 3.87 (s, 2H) 7.20 (d, J=8.60 Hz, 2H) 7.25 (d, J=8.60 Hz, 2H).
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