1: 91 percent / potassium hydroxyde / ethanol / 0.5 h / Ambient temperature 2: PBr3 / 4 h / 0 °C 3: 74 percent / tetrahydrofuran / 16 h / Heating 4: 82 percent / butyllithium / tetrahydrofuran; diethyl ether 5: 83 percent / butyllithium / tetrahydrofuran / -78 °C 6: 75 percent / s-collidine, LiCl, mesyl chloride / 2 h / 0 °C 7: 1.) THF, disiamylborane, -10 deg C 2.) benzene, Pd(PPh3)4, 4N-aqueous NaOH, reflux, 30 min View Scheme