1.1: lithium hydroxide hydrate / tetrahydrofuran; water / 72 h / 20 °C 1.2: pH 1 2.1: 4-(N,N-dimethlyamino)pyridine; diisopropyl-carbodiimide / dichloromethane / 12 h / 20 °C 3.1: QT / toluene / 24 h / 20 °C 4.1: sodium hypophosphite monohydrate / tetrahydrofuran; methanol / 1 h / 20 °C / pH 5.2 / aq. acetate buffer 5.1: lithium hydroxide hydrate / tetrahydrofuran; water / 3 h / 20 °C 5.2: pH 4 View Scheme

1: With lithium hydroxide hydrate in tetrahydrofuran; water T=20°C; 72 h; 2: With hydrogenchloride in tetrahydrofuran; water pH=1;