Synthesis of [c]-Fused Bicyclic Proline Analogues

An overview of synthetic methods developed to build [c]-fused bicyclic proline analogues is presented. The focus is on the preparation of azabicycles that bear a carbocyclic ring fused to the [c] face of the pyrrolidine unit. Attention is paid both to procedures that afford the desired compounds in racemic form and to asymmetric strategies. Procedures are organized according to the size of the carbocycle that is fused to the pyrrolidine moiety. Strategies able to provide multigram quantities of enantiopure compounds that have application in the synthesis of marketed drugs are highlighted.