Novel Synthetic Approaches for the Synthesis of Alanine-Proline Chimeras

In this review, we reported on the Proline-chimeras characterized by resembling the skeleton of Alanine (Alanine-Proline chimeras). The synthetic approaches were classified according to the position of the methyl group on the pyrrolidine ring. Moreover, the synthesis of pyroglutamic acid derivatives will be discussed due to its importance as building block and chiral pool in the asymmetric synthesis of numerous bioactive compounds. The present review will be focused on the chemical syntheses of mono-methyl substituted proline derivatives, including the contribution to the literature from 2004 to 2016.