1: bromobenzene With magnesium in diethyl ether 0.5 h; Reflux; 2: L-tert-butyl-leucine methyl ester hydrochloride in diethyl ether T=20°C; 24 h;

sodium tetrahydroborate in ethanol; water 5.5 h; Heating;

1: sodium hydrogencarbonate / dichloromethane; water / 2 h / Inert atmosphere; Cooling with ice 2: 4-(N,N-dimethlyamino)pyridine / toluene / 6 h / Inert atmosphere; Reflux 3: lithium hydroxide hydrate; water / methanol / 4 h / 60 °C / Inert atmosphere 4: N-ethyl-N,N-diisopropylamine; HATU / N,N-dimethyl-formamide / 20 °C / Inert atmosphere 5: dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II) dichloromethane adduct; triethylamine / ethanol / 1 h / Inert atmosphere; Reflux 6: Zhan 1b catalyst / 1,2-dichloro-ethane / 1 h / 90 °C / Inert atmosphere 7: palladium 10 on activated carbon; hydrogen / 1,4-dioxane; methanol / 2 h 8: lithium hydroxide hydrate; water / tetrahydrofuran / 18 h / 20 °C / Inert atmosphere View Scheme

1: sodium hydrogencarbonate / dichloromethane; water / 2 h / Inert atmosphere; Cooling with ice 2: 4-(N,N-dimethlyamino)pyridine / toluene / 6 h / Inert atmosphere; Reflux 3: lithium hydroxide hydrate; water / methanol / 4 h / 60 °C / Inert atmosphere 4: N-ethyl-N,N-diisopropylamine; HATU / N,N-dimethyl-formamide / 20 °C / Inert atmosphere 5: dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II) dichloromethane adduct; triethylamine / ethanol / 1 h / Inert atmosphere; Reflux 6: Zhan 1b catalyst / 1,2-dichloro-ethane / 1 h / 90 °C / Inert atmosphere 7: palladium 10 on activated carbon; hydrogen / 1,4-dioxane; methanol / 2 h 8: lithium hydroxide hydrate; water / tetrahydrofuran / 18 h / 20 °C / Inert atmosphere 9: 4-(N,N-dimethlyamino)pyridine; O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; N-ethyl-N,N-diisopropylamine / dichloromethane / 15 h / 20 °C / Inert atmosphere View Scheme