Synthesis of novel isoxazoline-fused cyclic β-amino esters by regio- and stereo-selective 1,3-dipolar cycloaddition

Isoxazoline-fused 2-aminocyclopentanecarboxylate derivatives were regio- and stereo-selectively synthesized by nitrile oxide 1,3-dipolar cycloaddition to cis- or trans-ethyl-2-aminocyclopent-3-enecarboxylates. The compounds were prepared in enantiomerically pure form by enzymatic resolution of the racemic bicyclic β-lactam.