[Cl:1][C:2]1[CH:3]=[C:4]([C@@H:8]2[C@@H:13]([C:14]3[CH:19]=[CH:18][C:17]([Cl:20])=[CH:16][CH:15]=3)[NH:12][C:11](=[O:21])[CH2:10][CH2:9]2)[CH:5]=[CH:6][CH:7]=1.[Li][CH2:23][CH2:24][CH2:25]C.C(Br)C=C>C1COCC1>[CH2:25]([C@@H:10]1[CH2:9][C@H:8]([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([Cl:1])[CH:3]=2)[C@@H:13]([C:14]2[CH:15]=[CH:16][C:17]([Cl:20])=[CH:18][CH:19]=2)[NH:12][C:11]1=[O:21])[CH:24]=[CH2:23]A 100 mL flame-dried round-bottomed flask equipped with a magnetic stir bar was charged with (5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)piperidin-2-one (1.32 g, 4.12 mmol) (Example 1, Step E) and anhydrous THF (41.2 mL). This solution was cooled to 0° C. under argon and BuLi (3.30 mL, 8.24 mmol) was added. After 10 minutes allyl bromide (0.357 mL, 4.12 mmol) was added. After an additional 45 minutes the reaction was quenched by the addition of sat. aq. NH4Cl and the layers were separated. The aqueous layer was extracted with EtOAc twice and the organics were pooled, washed with sat. aq. NaCl solution, dried (MgSO4), filtered and concentrated in vacuo to provide a colorless oil. Purification using a Combiflash Companion (flash column chromatography, Teledyne Isco, Lincoln, Nebr.) with a 120 g SiO2 column and eluting with 10 to 100% EtOAc/hexanes provided the title compound.
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