1: 56 percent / NaN3 / pyridine / 120 h / Ambient temperature 2: 95 percent / TBAF / tetrahydrofuran / 2 h / Ambient temperature 3: 88 percent / pyridine / 5 h / Ambient temperature 4: 1,) conc. H2SO4, 2.) pyridine, DMAP / 1.) 4 deg C, 6 d, 2.) room temperature, overnight 5: 1.) MSTFA, 2.) TMS-OTf / 1.) DCE, reflux, 30 min, 2.) DCE, 80 deg C, overnight 6: 52 percent / NH3 / tetrahydrofuran / 60 °C 7: 97 percent / H2 / Pd/C / ethanol / 6 h / 760 Torr View Scheme

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

1: 1.) MSTFA, 2.) TMS-OTf / 1.) DCE, reflux, 30 min, 2.) DCE, 80 deg C, overnight 2: 52 percent / NH3 / tetrahydrofuran / 60 °C 3: 97 percent / H2 / Pd/C / ethanol / 6 h / 760 Torr View Scheme

1: 52 percent / NH3 / tetrahydrofuran / 60 °C 2: 97 percent / H2 / Pd/C / ethanol / 6 h / 760 Torr View Scheme

1: 87.4 percent / NH3 / methanol / 4 °C 2: 95 percent / tetrahydrofuran; diethyl ether / 72 h / 20 °C 3: 94.3 percent / NaH / tetrahydrofuran / 1 h / -15 - -10 °C 4: 96.7 percent / aq. NaOH / methanol / 72 h 5: 91.8 percent / H2 / Pd/C / ethanol; H2O / 120 h / 20 °C / 1551.44 Torr View Scheme

2-methoxy-ethanol; hydrazine hydrate

barium dihydroxide

methanol; N-butylamine

1: xylene 2: butylamine; methanol View Scheme