Stereo- and regiospecific formation of a highly functionalized bridgehead tricyclic sultam

Tethering of a nitrone moiety to an olefin containing endocyclic sultam results in high yielding spontaneous intramolecular nitrone–olefin cycloaddition. The reaction proceeds with complete regio- and stereospecific control to establish three new chiral centers in the tricyclic products which incorporate an unusual bridgehead sultam motif. A transition state model for the remarkable regio- and stereochemistry is supported by NMR analysis and X-ray crystal diffraction. Three sites of chemical diversity are highlighted which make the tricyclic template an attractive combinatorial scaffold.