5-Vinyl-2-norbornene is epoxidized with tert-butyl, tert-amyl, or cumyl hyd
roperoxide in the presence of molybdenyl ethanediolate at either or both of
the double bonds of the hydrocarbon to afford preferentially 2,3-epoxy-5-v
inylnorbornane. The reactivity of tert-alkyl hydroperoxides correlates with
their structure characterized by the Taft polar substituent constants. The
rho* value found to be 1.08 confirms the electrophilic character of the ca
talytic hydroperoxide epoxidation and indicates a low polarity of the activ
ated complex of the reaction.