1: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 2: palladium 10 on activated carbon; hydrogen / methanol / 16 h / 20 °C / 760.05 Torr 3: sodium hydroxide / acetonitrile; water / 1 h / 20 °C View Scheme

1: triethylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C / |Cooling with ice 2: tetrahydrofuran; diethyl ether / 2 h / -78 - 20 °C / |Inert atmosphere 3: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 4: palladium 10 on activated carbon; hydrogen / methanol / 16 h / 20 °C / 760.05 Torr 5: sodium hydroxide / acetonitrile; water / 1 h / 20 °C View Scheme

1: triethylamine / tetrahydrofuran / 120 h / 70 °C 2: triethylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C / |Cooling with ice 3: tetrahydrofuran; diethyl ether / 2 h / -78 - 20 °C / |Inert atmosphere 4: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 5: palladium 10 on activated carbon; hydrogen / methanol / 16 h / 20 °C / 760.05 Torr 6: sodium hydroxide / acetonitrile; water / 1 h / 20 °C View Scheme