1: 93 percent / triethylamine / CH2Cl2 / 0.5 h / 0 - 20 °C 2: 91.5 percent / sodium azide / dimethylformamide / 5 h / 68 - 70 °C 3: 98 percent / H2 / PtO2 Adams catalyst / methanol / 3.5 h / 20 °C / 1810.02 - 2068.59 Torr View Scheme

1: With oxalyl dichloride; dimethyl sulfoxide in dichloromethane T=-78°C; 6.16 h; 2: With triethylamine in dichloromethane T=-78°C;