Nitrone and nitrile oxide cycloadditions to bicyclopropylidene. Rearrangement of the isoxazolidine adducts to 3-spirocyclopropane-4-pyridone derivatives

Abstract

The two-step nitrone or nitrile oxide cycloaddition–rearrangement thermal process applied to bicyclopropylidene gives 4-pyridone, 7-indolizinone, and 2-quinolizinone derivatives containing a spirocyclopropane linkage α to a carbonyl group.