1.1: sodium hydride / dichloromethane; N,N-dimethyl-formamide / 4 h / 23 °C 2.1: lithium hydroxide hydrate / tetrahydrofuran / 1.5 h / 35 °C 2.2: pH 4 3.1: diisopropyl-carbodiimide; benzotriazol-1-ol / dichloromethane / 2 h / 20 - 23 °C 4.1: hydrogen / 5 palladium on charcoal / methanol / 4 h / 65 °C / 7500.75 Torr View Scheme