Progress towards the synthesis of piperazimycin A: synthesis of the non-proteogenic amino acids and elaboration into dipeptides

This Letter describes the synthesis of the five non-proteogenic amino acids required for the total synthesis of piperazimycin A, and synthetic elaboration into multiple dipeptides. Importantly, this Letter details the first example of an elusive piperazic acid-piperazic acid coupling to form this key C5-C14 dipeptide.