Ionization potential norbornene

Ionization potential of Continued) butenone, 123 cyclic diacetylenes, 305 cyclohexene, 48, 102 cis-cyclooctene, 102 Zraus -cyclooctene, 102 DABCO, 81 dimethyl ether, 123 ethylene, 80, 319 formaldehyde, 123, 319 hydrogen atom, 55, 75 methanol, 123 methyl acetate, 123 methyl acrylate, 123 nitrous oxide (N2O), 172 norbornadiene, 48 norbornene, 48 oxetane, 123 tetrahydrofuran, 123 trimethylamine, 81 water, 123... 

The rate of epoxidation of alkenes is increased by alkyl groups and other ERG substituents, and the reactivity of the peroxy acids is increased by EWG substituents." These structure-reactivity relationships demonstrate that the peroxy acid acts as an electrophile in the reaction. Low reactivity is exhibited by double bonds that are conjugated with strongly EWG substituents, and very reactive peroxy acids, such as trifluoroperoxyacetic acid, are required for oxidation of such compounds. " Strain increases the reactivity of alkenes toward epoxidation. Norbornene is about twice as reactive as cyclopentene toward peroxyacetic acid." trani-Cyclooctene is 90 times more reactive than cyclohexene." Shea and Kim found a good correlation between relief of strain, as determined by MM calculations, and the epoxidation rate. ° There is also a correlation with ionization potentials of the alkenes. Alkenes with aryl substituents are less reactive than unconjugated alkenes because of ground state stabilization and this is consistent with a lack of carbocation character in the TS. 

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