1: 88 percent / pyridine / 5 h / Ambient temperature 2: 1,) conc. H2SO4, 2.) pyridine, DMAP / 1.) 4 deg C, 6 d, 2.) room temperature, overnight 3: 1.) MSTFA, 2.) TMS-OTf / 1.) DCE, reflux, 30 min, 2.) DCE, 80 deg C, overnight 4: 52 percent / NH3 / tetrahydrofuran / 60 °C 5: 97 percent / H2 / Pd/C / ethanol / 6 h / 760 Torr View Scheme