1: 86 percent / BBr3 / CH2Cl2 / 4 h / Ambient temperature 2: imidazole / dimethylformamide / 10.5 h / 50 °C 5: 88 percent / diethyl ether / 1 h / Ambient temperature 6: 88 percent / I2 / benzene / 1 h / Heating 7: 19 mg / n-butyllithium / diethyl ether / 0.03 h / -78 °C View Scheme

1: 86 percent / BBr3 / CH2Cl2 / 4 h / Ambient temperature 2: 5 mg / dimethylformamide / 3 h / 70 - 90 °C View Scheme