Synthesis of chirally pure 2,5‐disubstituted diketopiperazines derived from trisubstituted phenylalanines

Abstract Some new chirally pure 2,5‐substituted diketopiperazines were synthesized starting from 2‐methoxybenzyl alcohol. This multistep synthesis proceeds through the enzymatic synthesis of chirally pure amino acids, protection and dipeptide coupling, cyclization of dipeptide ester formates, and nitration of the resulting diketopiperazines.