Pyroglutamic Acid Derivatives: Building Blocks for Drug Discovery

Substituted prolines namely amino acid proline chimeras, have received a great synthetic efforts with the aim to develop a full library of compounds to be used in bioactive peptides drug discovery.Conversely pyroglutamic acid derivatives, strictly related to proline chimeras have been used only marginally in peptide modifications, probably due the lack of handled asymmetric syntheses.In this work we reviewed the "state of the art" on the synthetic approaches to pyroglutamic acid derivatives bearing a side chain related to that of natural amino acids.