Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8][O:9][Si:10]([C:13]([CH3:16])([CH3:15])[CH3:14])([CH3:12])[CH3:11])[N:3]=1.CCCCCC.[Li]CCCC.[CH3:28][C:29](N(C)C)=[O:30]>CCOCC.C1COCC1>[C:29]([C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8][O:9][Si:10]([C:13]([CH3:16])([CH3:15])[CH3:14])([CH3:12])[CH3:11])[N:3]=1)(=[O:30])[CH3:28]
To a stirred solution of 2-Bromo-6-(((tert-butyldimethylsilyl)oxy)methyl)pyridine (1.59 g, 5.26 mmol) in a mixture of ether, hexane and THF (2:1:1, 105 mL) was added n-BuLi (3.29 mL, 5.26 mmol, 1.6 M in hexane solution) dropwise at −78° C. during 5-10 min. To the resulting dark brown solution was dropped anhydrous DMA (0.74 mL, 7.89 mmol) at the same temperature. The reaction mixture was stirred for 30 min and then quenched with water (8 mL) and extracted with EtOAc. The organic layer was washed with water and brine and dried over MgSO4. After purification by column chromatography on silica gel (hexane/EtOAc 98:2) 0.78 g (56%) of the title compound as an oil were obtained. 1H NMR (CDCl3) δ 7.95 (d, 1H, J=7.5 Hz, H-3), 7.88 (t, 1H, J=7.6 Hz, H-4), 7.73 (t, 1H, J=7.6 Hz, H-5), 4.93 (s, 2H, CH2), 2.75 (s, 3H, CH3), 1.03 (s, 9H, (CH3)3C), 0.20 (s, 6H, (Me)2Si); 13C NMR (CDCl3) δ 200.8 (CO), 161.4 (C-6), 153.0 (C-2), 139.4 (C-4), 124.0 (C-5), 118.0 (C-3), 66.4 (CH2), 26.3 ((CH3)3C), 18.8 ((CH3)3C), -4.96 ((Me)2Si).
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