1: 69 percent / pyridine / 3 h / 110 °C 2: 94 percent / aq. TFA / 0.17 h / 20 °C 3: 80 percent / ZnCl2 / 5 h / 20 °C 4: 75 percent / NaBH3CN; TiCl4 / acetonitrile / 15 h / 0 °C 5: 61 percent / NaN(SiMe3)2 / tetrahydrofuran / 3 h / 20 °C 6: 100 percent / H2 / Pd/C / methanol / 15 h / 20 °C View Scheme

1.1: 69 percent / pyridine / 3 h / 110 °C 2.1: 94 percent / aq. TFA / 0.17 h / 20 °C 3.1: 80 percent / ZnCl2 / 5 h / 20 °C 4.1: 75 percent / NaBH3CN; TiCl4 / acetonitrile / 15 h / 0 °C 5.1: 61 percent / NaN(SiMe3)2 / tetrahydrofuran / 3 h / 20 °C 6.1: 100 percent / H2 / Pd/C / methanol / 15 h / 20 °C 7.1: 84 percent / NaN3; NBS / 1,2-dimethoxy-ethane; H2O / 27 h / 20 °C 8.1: (NH4)2SO4 / 24 h / Heating 8.2: PdCl2; PPh3 / tetrahydrofuran; hexane / 67 h / Heating 8.3: 57 percent / aq. NH4Cl / methanol / 5 h / Heating View Scheme