In an effort to design a dipeptide structural mimic of protein and peptide β-turns, we have prepared and evaluated the conformation of derivatives of the novel, highly constrained ten- membered lactam,(3 S, 10 S)-(6 E)-2-azacyclodec-6-enone (1). A synthetic route utilizing ring-closing olefin metathesis (RCM) has been used to prepare this novel ten-membered ring in high yield. X-ray crystallography and 1H NMR analysis have established that ring ...