Asymmetric Diels-Alder reaction of β,β-disubstituted enals and chromone-fused dienes: construction of collections with high molecular complexity and skeletal diversity

An asymmetric inverse-electron-demand Diels-Alder reaction of chromone-fused dienes and beta, beta-disubstituted alpha,beta-unsaturated aldehydes has been developed via dienamine catalysis. Different domino or sequential transformations could be carried out for electron-deficient dienes with variously substituted patterns, allowing for the efficient construction of caged or fused tetrahydroxanthones with high molecular complexity and skeletal diversity in excellent diastereo- and enantioselectivities.