1: 86 percent / Br2; AlCl3 / CH2Cl2 / 0.5 h / 0 °C 2: 77 percent / p-TsOH*H2O / methanol / 24 h / Heating 3: 99 percent / MeLi*LiBr / diethyl ether; various solvent(s) / 1 h / 20 °C View Scheme

1: 86 percent / Br2; AlCl3 / CH2Cl2 / 0.5 h / 0 °C 2: 77 percent / p-TsOH*H2O / methanol / 24 h / Heating 3: 99 percent / MeLi*LiBr / diethyl ether; various solvent(s) / 1 h / 20 °C 4: n-BuLi / tetrahydrofuran; hexane / 3 h / -78 - 20 °C 5: 1.42 g / aq. HCl / tetrahydrofuran / 0.5 h / 20 °C View Scheme