Synthesis of β-Lactones by the Regioselective, Cobalt and Lewis Acid Catalyzed Carbonylation of Simple and Functionalized Epoxides

The PPNCo(CO)(4) and BF(3) x Et(2)O catalyzed carbonylation of simple and functionalized epoxides in DME gives the corresponding beta-lactones regioselectively in good to high yields. The carbonylation occurred selectively at the unsubstituted C-O bond of the epoxide ring, and this reaction tolerates various functional groups such as alkenyl, halide, hydroxy, and alkyl ether.