1.1: triethylamine / dichloromethane / 2 h / 20 °C / Inert atmosphere 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / dichloromethane / 4 h / 20 °C / Inert atmosphere 3.1: methanol / 3 h 4.1: BOP-Cl; triethylamine / acetonitrile / Inert atmosphere 5.1: lithium hydroxide hydrate / tetrahydrofuran; water / 2 h / 20 °C 5.2: pH 3 6.1: dichloromethane / 2 h / 20 °C 7.1: diphenyl phosphoryl azide / N,N-dimethyl-formamide / 2 h / 20 °C View Scheme