A new route to γ-arylidenebutyrolactones via a tandem carbopalladation-heterocyclisation sequence: A formal synthesis of U-68,215
Benzo-annulated enol lactones are obtained in good yields from pentynoic acids 3- or 5-substituted with an iodo-aryl moiety by palladium-catalyzed cyclization of their potassium carboxylates. Using this approach, an efficient new route to U-68,215 is described.