To a stirred solution of copper(II)bromide dimethylsulfide complex (6.85 g, 33.3 mmol) in anhydrous THF (60 mL) and dimethylsulfide (30 mL) was added 4-fluorophenylmagnesium bromide (30.0 mL, 1.0 M in THF, 30.0 mmol) at −40° C. The resultant mixture was stirred at −40° C. for 30 min, then warmed to −10° C. The product from Step A (1.18 g, 5.10 mmol) in THF (30 mL) was added to the above reaction mixture over 1 h at −10° C. The resultant mixture was stirred at −10° C. for 2 h, then slowly warmed to room temperature and stirred at room temperature for 12 h. The reaction was quenched by slow addition of saturated aqueous ammonium chloride solution. The organic phase was separated and the aqueous phase was extracted with two portions of ethyl acetate. The combined organic layers were washed with brine and concentrated in vacuo. Purification by flash chromatography (silica gel, 80:20 hexanes/ethyl acetate) afforded the desired product.
