Highly diastereoselective thermal decomposition of 3-(azidomethylene)dihydrofuran-2-one

Thermal decomposition of 3-(azidomethylene)dihydrofuran-2-one in various solvents at temperatures above 70°C gave a spiroaziridine derivative with an excellent diastereoselectivity. A mechanism of this new kind of substituted vinyl azide decomposition has been suggested based mainly on the stereochemistry and kinetic data of the reaction. A spiroazirine derivative proposed as a reaction intermediate was trapped by the decomposition of title azide in acetic anhydride.