1: 75 percent / sodium azide / dimethylsulfoxide / 36 h / 80 °C 2: 1.) hydrogen, 2.) sodium methoxide / 1.) palladium hydroxide on carbon / 1.) methanol, 6 h, 2.) methanol, reflux, 60 h 3: 94 percent / borane-methyl sulfide complex / tetrahydrofuran / 0 deg C, 30 min, room temperature, 2 h 4: 96 percent / conc. HCl / tetrahydrofuran / 12 h / Ambient temperature View Scheme