1: 89 percent / DBU / CH2Cl2 / 8 h / Ambient temperature 2: 40 mg / Et3N / CH2Cl2 / 0.25 h / 0 °C 3: 90 percent / LiN3 / dimethylformamide / 18 h / Ambient temperature 4: 59 percent / H2 / 10 percent Pd/C / ethyl acetate / 3 h / Ambient temperature View Scheme