Synthesis of the Southern Tripeptide (C₁–N₁₂) of Sanglifehrins Using Asymmetric Organocatalysis

The tripeptide southern region of the novel cyclophilin binding natural product macrolides, namely sanglifehrins, is synthesized involving asymmetric organocatalysis as chirality-inducing step. List's asymmetric α-amination was used in the synthesis of the m-hydroxyphenylalanine part, whereas α-hydrazination was used for the piperazic ester part.