ESR evidence for the stereospecific spin trapping of 5‐alkyl‐5‐methyl‐1‐pyrroline N‐oxides

The ability of ten cyclic nitrones, 5-alkyl-5-methyl-1-pyrroline N-oxides, to trap a variety of short-lived free radicals has been investigated using ESR spectroscopy. Stereospecific spin trapping by these nitrones has been demonstrated by comparison of the ESR spectra of their adducts with the ESR spectra of the corresponding 5-alkyl-5-methyl-1-tetrahydropyrrolyl-1-oxyls. Phenyl radical trans addition to these nitrones has also been proved.