Carboxylative cyclization of substituted propenyl ketones using CO2: transition-metal-free synthesis of α-pyrones

Carbon dioxide is a green carboxylative reagent due to its nontoxic and renewable properties. Described herein is a carboxylative cyclization of substituted 1-propenyl ketones via gamma-carboxylation using CO2, which provides an efficient, transition-metal-free and straightforward access to important alpha-pyrone compounds from easily available substrates and CO2.