Intramolecular Diels–Alder reaction of new building blocks, N-substituted 3,5-dihydro-1H-thieno[3,4-c]-pyrrole S,S-dioxides; a general route to the tricyclic azanorbornane framework
Abstract
In spite of the absence of activating groups for dienophiles, N-substituted 3,5-dihydro-1H-thieno[3,4-c]pyrrole S,S-dioxides 1 which contain terminal olefin substituents, undergo facile intramolecular Diels–Alder reaction and subsequent spontaneous desulfonylation to give the corresponding tricyclic azanorbornane framework 2 in good yields.