To a solution of 4-(3-fluoro-4-trifluoromethyl-phenyl)-6,7-dihydro-5H-[2]pyrindine (76.0 mg, 0.27 mmol) and dirhodium(II, III) tetrakis caprolactamate (1.8 mg, 0.0027 mmol; synthesis described in M. P. Doyle et al., J. Am. Chem. Soc. 1993, 115, 958-964) in dichloromethane (0.5 mL) was added sodium bicarbonate (22.7 mg, 0.27 mmol) and tert-butyl hydroperoxide (0.25 mL, 1.35 mmol). The reaction mixture was stirred at room temperature for 48 h. During this time period additional equivalents of tert-butyl hydroperoxide (1.25 mL, 6.75 mmol) were added in small portions. The solvent was removed under reduced pressure and the crude reaction mixture purified by flash chromatography (20 g SiO2, Telos-cartridge) eluting with a 0 to 50% EtOAc-heptane gradient to provide 15.5 mg (19%) of 4-(3-fluoro-4-trifluoromethyl-phenyl)-5,6-dihydro-[2]pyrindin-7-one (intermediate A-14 [C1]) as slightly yellow solid; MS: 296.1 (M+H)+; and 17.4 mg (22%) of 4-(3-fluoro-4-trifluoromethyl-phenyl)-6,7-dihydro-[2]pyrindin-5-one (intermediate A-14 [C2]) as slightly yellow solid. MS: 296.4 (M+H)+.
