1: hydrogen; palladium on activated charcoal / methanol / 15 h 2: 1,8-diazabicyclo[5.4.0]undec-7-ene; diphenyl phosphoryl azide / tetrahydrofuran / 25 h / 0 - 20 °C / |Inert atmosphere 3: hydrogen; palladium on activated charcoal / ethyl acetate 4: potassium carbonate; water / methanol / 12 h View Scheme