1: 56 percent / pyridine / benzene / 1.5 h / 20 °C 2: H2 / Lindlar catalyst / various solvent(s) 3: TBAF / tetrahydrofuran / 1.5 h / 20 °C 4: 0.31 g / TsOH*H2O / methanol / 2.5 h / 20 °C 5: aq. NaOH / methanol / 0.5 h / 70 °C 6: H2 / Pd/C / 760 Torr View Scheme