The Chemistry of 5-Oxodihydroisoxazoles. XVI. A New Synthesis of Pyrroles, Furans, Thiophens and Their Benzo Analogues

Ethyl 5-oxo-2-phenyl-2,5-dihydroisoxazole-4-carboxylate (2) was photolysed at 300 nm in the presence of phenols, enols, anilines, enamines , aryl thiols and thioenols affording enamines. Treatment of these enamines with Lewis or protic acids gives the respective benzo and five- membered ring systems.