Stereocontrolled access to δ-lactone-fused-γ-lactams bearing angular benzylic quaternary stereocenters

Abstract

The catalytic halolactonization of readily affordable γ-lactam-tethered alkenoic acids has facilitated the site-selective, efficient, and stereocontrolled synthesis of halogenated fused γ-lactam-δ-lactones.

Contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids for the flexible and stereocontrolled synthesis of fused lactam-halolactones

“…Our interest in the synthesis and post-diversification of lactam-tethered alkenoic acids 19 prompted us to explore a practical and flexible route toward sp 3 -rich fused lactam-lactones bearing quaternary and contiguous stereocenters. Toward this end, we sought to interrogate readily available lactam-bearing 5-aryl-4( E )-pentenoic acids of type 1, 20 a in a contra-thermodynamic and catalytic halolactonization protocol ( Fig. 2C ).…”