1.1: lithium hydroxide hydrate / tetrahydrofuran; water / Inert atmosphere 1.2: Inert atmosphere 2.1: 4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide / dichloromethane / 1 h / Inert atmosphere 3.1: dichloromethane / 2 h / Inert atmosphere 4.1: water; isopropyl alcohol / 37 °C / pH 7.4 / aq. phosphate buffer View Scheme

1.1: trifluoroacetic acid / dichloromethane / 2 h / 0 °C 1.2: 2 h / 0 - 10 °C 2.1: phosphoric acid dibutyl ester / toluene / 5 h / 110 °C View Scheme

1: With lithium hydroxide hydrate in tetrahydrofuran; water Inert atmosphere; 2: With hydrogenchloride in tetrahydrofuran; water Inert atmosphere;