1: 1.) LiN3, 2.) aq. H2SO4 / 1.) DMF, 105 deg C, 2.5 h, 2.) THF, 50 deg C, 30 min 2: 96 percent / pyridine / CH2Cl2 / 0.5 h / 0 °C 3: 89 percent / tetrahydrofuran / 3 h / 80 °C 4: 98 percent / NaOMe / methanol / 6 h / Ambient temperature 5: H2 / Raney nickel / ethyl acetate / 18 h / Ambient temperature 6: Na, NH3 / tetrahydrofuran / 1.5 h / -40 °C View Scheme