A novel modification of the Ritter reaction: stereoselective synthesis of bridgehead-fused Δ2-norbornanethiazolines from thiocamphor and thiofenchone

An easy two-step route for the stereoselective synthesis of novel bridgehead-fused norbornanethiazolines from readily available natural camphor and fenchone is described. The key step of the synthetic route is the highly stereoselective trapping of 1-(trifluoromethylsulfonylthio)-2-norbornyl cations by nitriles followed by intramolecular cyclization, which constitutes a new modification of the Ritter reaction.