Br[C:2]1[CH:3]=[C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[O:5][CH:6]=1.[Li]CCCC.C(O[B:22]1[O:26][C:25]([CH3:28])([CH3:27])[C:24]([CH3:30])([CH3:29])[O:23]1)(C)C>C1COCC1>[CH3:29][C:24]1([CH3:30])[C:25]([CH3:28])([CH3:27])[O:26][B:22]([C:2]2[CH:3]=[C:4]([C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=3)[O:5][CH:6]=2)[O:23]1To a solution of 4-bromo-2-phenylfuran (1.3 g, 5.8 mmol) in THF (15 mL) was added n-BuLi (2.5M, 2.8 mL, 7.0 mmol) at −78° C. The reaction mixture was kept at −55° C. for 15 min and then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.3 g, 7.0 mmol) was added at −78° C. The reaction mixture was stirred for 1.5 h and then poured into water/ice solution, extracted with petroleum ether (3×50 mL), dried over anhydrous sodium sulfate and then concentrated in vacuo to give a residue, which was purified by silica gel column chromatography (1% ethyl acetate in petroleum ether) to afford 4,4,5,5-tetramethyl-2-(5-phenylfuran-3-yl)-1,3,2-dioxaborolane as a red oil (300 mg, 19%).
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