C([Li])CCC.Br[C:7]1[C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[O:9][CH:8]=1.[CH:16]([N:29]1[CH2:32][C:31](=[O:33])[CH2:30]1)([C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.O>C1COCC1>[CH:16]([N:29]1[CH2:32][C:31]([C:8]2[O:9][C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=3[CH:7]=2)([OH:33])[CH2:30]1)([C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1A 2.5 M solution of n-butyllithium in hexanes (2.23 mL, 5.58 mmol) was added dropwise to a solution of 3-bromobenzofuran (1.0 g, 5.08 mmol) in THF (35 mL) at −78° C. The reaction mixture was stirred for 30 minutes at −78° C. and then a solution of 1-benzhydrylazetidin-3-one (1.2 g, 5.08 mmol, as prepared in step 1 of example FAB270) in THF (10 mL) was added dropwise at the same temperature. The mixture was allowed to warm back to room temperature overnight. Water (50 mL) was added and the mixture was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated. The residue was purified by chromatography on silica gel using petroleum ether/dichloromethane (50:50 to 0:100) as eluent. The title compound was obtained as a yellow solid (230 mg, 13%).
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