反应详情

A solution of 11 (100 mg, 0.44 mmol) in THF (5 mL) was sequentially treated with BF3.OEt2 (58 μL, 0.46 mmol), n-BuLi (0.51 mL, 1.70 M, 0.87 mmol) and DMF (0.17 mL, 2.18 mmol). Standard workup followed by gradient column chromatography (silica gel, 94:5:1 hexanes/Et2O/Et3N, then 84:15:1 hexanes/Et2O/Et3N) gave 12d (85 mg, 76%) as a red-orange oil; IR (KBr, neat) vmax 3097, 2943, 2851, 2826, 2785, 1667 cm−1, 1H NMR (300 MHz, CDCl3) 10.13 (s, 1H), 4.61 (m, 1H), 4.40 (t, 1H, J=2.7 Hz), 4.29 (m, 1H), 4.27 (s, 5H), 2.70 (s, 6H) ppm; 13C NMR (75.5 MHz, CDCl3) 192.8, 117.5, 71.8, 69.5, 67.7, 66.2, 60.2, 45.6 ppm; EIMS [m/z (%)] 257 (M+, 100), 229 (13), 119 (54), 44 (66); HRMS (EI) calcd for C13H15NO56Fe: 257.0503. Found 257.0504.