Mimics of Peptide Turn Backbone and Side-Chain Geometry by a General Approach for Modifying Azabicyclo[5.3.0]alkanone Amino Acids

Peptide mimics with constrained backbone and side-chain geometry are important tools for studying structure activity relationships of biologically active candidates. A general method for creating beta-turn mimics possessing side-chain diversity has been developed featuring diastereoselective S(N)1 displacements of an iodide precursor. In particular, 6-iodo-pyrroloazepin-2-one amino ester 10 has served as a common precursor in reactions with a variety of alcohol, phenol, nitrate, and azide nucleophiles to provide an array of constrained peptide mimics.