Synthesis of oxepine-, oxocine- and azepine-annulated carbazole derivatives by combined Claisen rearrangement and diene/enyne metathesis

A new route to various medium ring heterocycle-annulated tetra-, penta- and hexacyclic carbazole derivatives has been developed using successive applications of three atom economic processes, viz. Claisen rearrangement, olefin metathesis and Diels-Alder reactions.