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Published on: August 18, 2012
Electron spin resonance study of free radicals generated from retinyl- and ionyl-derivatives
1Department of Chemistry, University of St Andrews, Fife, U.K.
Abstract:
Free radicals generated from alpha- and beta-ionyl bromides gave well resolved ESR spectra, but retinyl bromide and chloride gave only broad signals. Delocalised radicals were also spectroscopically observed on hydrogen abstraction from alpha-ionane, alpha-ionyltrimethylsilylether and buten-3-ynyl-2,6,6-trimethyl-2-cyclohexene. Retinyl and beta-ionyl radicals, derived from the corresponding xanthates, were successfully spin trapped with nitrosodurene. The results suggested that the secondary sites C(7) and C(9) were the most reactive in the beta-ionyl radical and that the secondary sites C(7) and C(11) and probably the primary site C(15) were the most reactive in the retinyl radical.
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