Unprecedented and novel hetero [6+3] cycloadditions of fulvene: a facile synthesis of the 11-oxasteroid framework

Abstract

In contrast to the Diels–Alder reaction of fulvenes and benzoquinone, 6-dimethylaminofulvene reacts with benzoquinones to give the hetero [6+3] cycloaddition adduct, constituting an efficient and novel route to cyclopenta[c]chromenes including 11-oxasteroids.