Explorations of an intramolecular route to pyrrolo[3,4-b]isoxazoles: an unexpected retro-Claisen reaction

Potential precursors have been prepared for intramolecular 1,3-dipolar cycloaddition to form a pyrrolo[3,4-b]isoxazole. The cycloaddition has not to date been accomplished, however an unexpected retro-Claisen reaction is reported.