I[C:2]1[CH:3]=[CH:4][C:5]([CH3:8])=[N:6][CH:7]=1.[Li]C(C)(C)C.Cl([O-])(=O)(=O)=O.[CH2:19]1[C:26]2[CH2:25][CH2:24][CH2:23][N+:22]=2[CH2:21][CH2:20]1>CCOCC.CCCCC>[CH3:8][C:5]1[N:6]=[CH:7][C:2]([C:26]23[CH2:25][CH2:24][CH2:23][N:22]2[CH2:21][CH2:20][CH2:19]3)=[CH:3][CH:4]=1
5-Iodo-2-methylpyridine (345 mg, 1.39 mmol) was dissolved in Et2O and cooled to -95° C. A solution of 2.5M t-BuLi (1.7M in pentane, 1.8 mL, 3.06 mmol) in pentane was added dropwise. 1,2,3,5,6,7-hexahydropyrrolizinium perchlorate (435 mg, 2.1 mmol) was added, and the reaction mixture was allowed to warm to -10° C. with stirring for 2 hours. The cold bath was removed, 2N HCl was added, and the phases were separated. The aqueous phase was basified with 15% NaOH and extracted with CH2Cl2 (2×). The CH2Cl2 fractions were combined, dried (MgSO4) and concentrated, and the residue was chromatographed (silica gel; CHCl3 /MeOH, 95:5) to afford the title compound as an oil (126 mg, 45%): 1H NMR (CDCl3, 300 MHz) δ1.57-1.71 (m, 2H), 1.77-2.05 (m, 6H), 2.52 (s, 3H), 2.64-2.72 (m, 2H), 3.12-3.19 (m, 2H), 7.05 (d, J=8.1 Hz, 1H), 7.71 (dd, J=8.1, 2.6 Hz, 1H), 8.56 (d, J=2.6 Hz, 1H); MS (CI/NH3) m/z: 203 (M+H)+.
Wird geladen…
