Some 4-substituted arylnitriloxides undergo 1, 3-dipolar cycloadditions with 5-methylene (5H) furan-2-one (protoanemonin) with formation of spiroisoxazolines. These spiroadducts can be opened to the corresponding (2E)-3-(3′-arylisoxazol-5′-yl) propenoic acids 5 and 3-aryl-5 [4′-(3′-aryl-4′, 5′-dihydroisoxazolinyl)] isoxazole 6 by various ways, including acidic and basic treatments, as well as electrooxidation. In the latter case, the electron ...
![3,3'-diphenyl-3a,6a-dihydro-4-oxospiro[isoxazolino-5',6-isoxazolo[3,4-c]furanone] Structure](https://image.chemsrc.com/caspic/286/292605-26-6.png)
