From Macrocycle Dipeptide Lactams To Azabicyclo[X.Y.0]alkanone Amino Acids:  A Transannular Cyclization Route for Peptide Mimic Synthesis

Macrocyclic and fused bicyclic dipeptides are complementary motifs for mimicry of different types of β-turn geometry. Macrocyclic dipeptide mimics have served as precursors for the synthesis of their bicyclic counterparts using electrophilic transannular cyclizations of 9- and 10-membered ring lactams 9−12 to form azabicyclo[4.3.0]- and -[5.3.0]alkanone amino esters 13−16.