Multicomponent Domino Synthesis of Cyclopenta[b]furan-2-ones

A stereoselective multicomponent reaction involving Meldrum’s acid, a conjugated dienal, and an alcohol is reported. Valuable cyclopenta[b]furan-2-ones are obtained as products of this straightforward transformation, which is accompanied by the formation of four stereocenters, two new cycles, and four new bonds (two C–C and two C–heteroatom). A reaction mechanism was elaborated involving an initial Knoevenagel condensation followed by cycloisomerization and eventual fragmentation.