ChemInform Abstract: Dually Activated Michael-Michael-Acetalization Cascade: Facile and Highly Diastereoselective Construction of Tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one Polycyclic Scaffold

A Michael-Michael-acetalization cascade between 4-(2-hydroxyphenyl)but-3-en-2-ones and α,β-unsaturated aldehydes via a novel dual activation mode promoted by pyrrolidine was successfully established. Consequently, various novel tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one derivatives were prepared in excellent diastereoselectivities and moderate to good yields. Further diverse modification of the resulting tricyclic scaffolds provided a facile pathway to achieve a variety of tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one analogs.