1.1: 4-(N,N-dimethlyamino)pyridine; N-ethyl-N,N-diisopropylamine / dichloromethane / 0 - 40 °C 2.1: triethylsilane; titanium tetrachloride / dichloromethane / -78 - -10 °C 3.1: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C 4.1: 2,6-dimethylpyridine / chloroform / 6 h / 20 - 55 °C 5.1: zirconium tetrachloride; isopropyl alcohol / 4 h / 50 °C 6.1: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C 7.1: hydrogen / ethanol 7.2: 50 °C View Scheme

1: 4-(N,N-dimethlyamino)pyridine; N-ethyl-N,N-diisopropylamine / dichloromethane / 0 - 40 °C 2: triethylsilane; titanium tetrachloride / dichloromethane / -78 - -10 °C 3: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C 4: 2,6-dimethylpyridine / chloroform / 6 h / 20 - 55 °C 5: zirconium tetrachloride; isopropyl alcohol / 4 h / 50 °C 6: hydrogen azide; triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran; benzene / 10 - 20 °C View Scheme