1: 92 percent / n-BuLi / tetrahydrofuran / 2 h / 25 °C 2: 97 percent / H2 / 10percent Pd-C / ethyl acetate / 25 °C 3: p-TsOH / methanol / 1.5 h / 40 °C 4: K2CO3 / benzene / 25 °C 5: p-TsOH, 4-Angstroem sieves / benzene / 2 h / Heating View Scheme