Auto tandem triple cascade organocatalysis: access to bis-lactone and butenolide derivatives

The synthesis of bis-lactone and butenolide derivatives was described using alkylidene Meldrum's acid as nucleophiles. The process operates in a triple cascade through an auto tandem catalysis promoted by DBU. A triple cascade auto tandem process catalyzed by the same catalytic specie leads to bis-lastone and butenolides in a stereoselective manner.