Br[C:2]1[CH:7]=[CH:6][C:5]([Si:8]([CH3:11])([CH3:10])[CH3:9])=[CH:4][CH:3]=1.II.[Mg].[O:15]=[C:16]1[CH2:19][N:18]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:17]1>C1COCC1>[OH:15][C:16]1([C:2]2[CH:7]=[CH:6][C:5]([Si:8]([CH3:11])([CH3:10])[CH3:9])=[CH:4][CH:3]=2)[CH2:17][N:18]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:19]1A 2 L-3neck flask equipped with mechanical stirrer, thermocouple, addition funnel and nitrogen inlet was charged with (4-bromophenyl)trimethylsilane (80.4 g, 0.35 mol), THF (600 mL), Mg (8.5 g), and I2 (catalytic amount). The suspension was refluxed at 68° C. for 1.5 hours until all magnesium disappeared. The solution was cooled to 0° C. in ice-bath. Then, a solution of tert-butyl 3-oxoazetidine-1-carboxylate (Preparation 2, 30 g, 0.17 mol) in THF (200 mL) was added slowly via addition funnel. The solution was stirred at 0° C. for 3 hours. LC/MS indicated the formation of desired product. The reaction was quenched with brine at 0° C. The aqueous layer was extracted with EtOAc (2×800 mL). The combined organics were dried over sodium sulfate, filtered and concentrated to give the desired product (47.4 g, 84% yield). 1H NMR (CDCl3) δ 7.3 (d, 2H), 7.2 (d, 2H), 4.0 (d, 2H), 3.9 (d, 2H), 2.9 (s, 1H), 1.2 (s, 9H), 0.0 (s, 9H).
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