Stereocontrolled synthesis of some novel functionalized heterocyclic amino ester and amide derivatives with multiple stereocenters

Abstract

The synthesis of some novel functionalized fused-ring β-amino lactones and lactams with multiple chiral centers has been attempted from readily available strained bicyclic β-amino acids via a stereocontrolled synthetic route. The key step was ring-rearrangement metathesis of allyl/propargyl esters or N-allylated/N-propargylated amides of (oxa)norbornene β-amino acids. The RRM transformations [ring-opening metathesis (ROM)/ring-closing metathesis (RCM) or ring-opening metathesis (ROM)/ring-closing enyne metathesis (RCEYM)] have been investigated using some commercially available catalysts. Importantly, the procedure used in this synthetic process does not affect the configurations of the chiral centers. This means that the structure of the starting (oxa)norbornene β-amino acids predetermines the configuration of the formed products.