Asymmetric Diels−Alder Reactions of 2-Pyrones with a Bifunctional Organic Catalyst

The reactions of 2-pyrones with electron-deficient dienophiles constitute a synthetically useful class of Diels−Alder reaction. By exploring cinchona alkaloid-derived organic molecules as acid−base bifunctional catalysts, we successfully developed the first highly enantioselective and diastereoselective catalytic Diels−Alder reaction with 2-pyrones. Furthermore, we demonstrated the possibility of using such catalysts to control the endo/exo selectivity in a Diels−Alder reaction.