N-Heterocyclic Carbene-Catalyzed Ireland-Coates Claisen Rearrangement: Synthesis of Functionalized β-Lactones

The N-heterocyclic carbene (NHC)-catalyzed Claisen rearrangement of hybrid Ireland-Coates structures has been achieved, allowing the stereoselective synthesis of highly functionalized beta-lactones. The reaction proceeds with high diastereoselectivity (>20:1) and affords a diverse range of beta-lactone fused cyclopentanes. Mechanistic studies are detailed.