Synthesis of β-lactones by the regioselective, cobalt and Lewis acid catalyzed carbonylation of simple and functionalized epoxides

The PPNCo(CO)(4) and BF3. Et2O 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.