RuO 4-catalyzed oxidation reactions of isoxazolino-2-azanorbornane derivatives: a short-cut synthesis of tricyclic lactams and peptidomimetic γ-amino acids

Abstract

A rapid access to peptidomimetic conformationally constrained γ-amino acids has been developed through the efficient RuO 4-mediated oxidation of regioisomeric isoxazolino-2-azanorbornane derivatives. The key intermediates are tricyclic lactams, which are quantitatively hydrolyzed into the desired amino acids. The conformational analysis, conducted by means of DFT calculations, supports the use of these γ-amino acids as β-turn inducers in peptide synthesis.