An efficient approach to angular tricyclic molecular architecture via Nazarov-like cyclization and double ring-expansion cascade

Abstract

Effective methods for accessing polycarbocycles are scarcely reported and generally involve complex, multistep transformations, thus restricting practical utility. Here, the authors construct tri-to-penta- cyclic frameworks containing at least two quaternary carbon centers via a tandem Nazarov-like cyclization / double cycloexpansion of simple 1,3-dicyclobutylidene ketone substrates.