Nitrones and oxaziridines. XVII. Photorearrangement of 3-Oxo-1-pyrroline 1-Oxides: A new route to Azetidin-2-ones

Abstract

Several 3-0x0-1-pyrroline I-oxides (1) undergo photorearrangement to the isomeric acyl azetidinones (3) and/or oxazinones (4) in ratios depending on the nature of their 2-substituents. The azetidinones can be isolated pure in moderate yield from reaction mixtures. In the case of 3-oxo-2-phenyl-l- pyrroline 1-oxide (la), the isomeric oxaziridine (2a) is established as an intermediate in the photorearrangement.