Synthesis, purification and conformational studies on enkephalin derivatives containing Λ‐amino‐n‐butyric acid

The solid-phase synthesis of several analogs of enkephalin containing Λ-amino-butyric acid is reported. Synthetic strategies, purification methods, chemical and physicochemical characterization are discussed. The n.m.r. data suggest for some of the analogs structural features similar to the opioids.