(S)-tert-butyl 3-methyl-2-(pyrrolidin-1-yl)butanoate

(S,E)-tert-butyl 2-isopropyl-2-(pyrrolidin-1-yl)-4-(p-toluenesulfonyl)but-3-enoate

cyclo<-Tyr-Arg-D-Lys-Asp-D-Val->*2AcOH