Chiral Iminoesters Derived from d‑Glyceraldehyde in [3 + 2] Cycloaddition Reactions. Asymmetric Synthesis of a Key Intermediate in the Synthesis of Neuramidinase Inhibitors

Silver-catalyzed endo-selective and copper-catalyzed exo-selective asymmetric [3 + 2] cycloadditions of acrylates to chiral iminoesters derived from d-glyceraldehyde have been investigated. The reaction diastereoselectively provides highly functionalized pyrrolidines. This approach was used to develop the first asymmetric synthesis of a key intermediate in the synthesis of pyrrolidine influenza neuramidinase inhibitors.