1: 84 percent / tetra-n-butylammonium fluoride / tetrahydrofuran; H2O / 1.5 h / 0 °C 2: 90 percent / DMAP / pyridine / 16 h / 2 °C 3: 75 percent / sodium azide / dimethylsulfoxide / 36 h / 80 °C 4: 1.) hydrogen, 2.) sodium methoxide / 1.) palladium hydroxide on carbon / 1.) methanol, 6 h, 2.) methanol, reflux, 60 h 5: 94 percent / borane-methyl sulfide complex / tetrahydrofuran / 0 deg C, 30 min, room temperature, 2 h 6: 96 percent / conc. HCl / tetrahydrofuran / 12 h / Ambient temperature View Scheme