Transition Metal Catalyzed Approaches to Lactones Involving CO Bond Formation

Metathetic Synthesis of Common and Medium-Sized Lactones: The State of the Art

“…Most often, the ring-closure reaction represents the crucial step in synthetic pathways to important natural products. In this respect, methods based on organometallic reagents or catalysts, such as carbonylation, carboxylation, and hydroacylation processes, have become increasingly important due to the possibility to control and direct the efficiency and selectivity of the lactone ring formation by appropriate tuning of the metal coordination sphere [41,42].…”