1: 56 percent / lithium azide / dimethylformamide / 24 h / 100 °C 2: 80 percent / aq. TFA / 2 h / 20 °C 3: 78 percent / imidazole / dimethylformamide / 72 h / 20 °C 4: hydrogen / Raney nickel / methanol / 24 h / 3620.04 Torr 5: 22 percent / potassium carbonate / acetone / 20 °C 6: 90 percent / TBAF*3H2O / tetrahydrofuran / 4 h / 20 °C View Scheme