Synthesis of orthogonally protected optically pure ketopiperazine, diketopiperazine, ketodiazepane, and 3-aminopyrrolidone building blocks for peptidomimetic combinatorial chemistry
convenient synthesis of orthogonallyprotected multi-tethered, optically pure 2-ketopiperazine, diketopiperazine, 2-ketodiazepane and 3-aminopyrrolidone scaffolds for Fmoc combinatorialchemistry has been developed. It utilizes accessible chiral amino acid precursors, sequentially applying reductive alkylation, dipeptide coupling and regioselective ring formation as key steps. These scaffolds are expansion