Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



The 5-aethylene-2-norbornene system, which contains two double bonds of unequal energies, appears to be a unique tool which can be used in distinguishing the two types of electrophilic and the two types of cycloaddition reactions. Previous experimental evidence as well as the data presented here show that electrophiles which form bridged, three-membered intermediates in their addition to olefins all attack at the higher energy endocyclic double bond. Electrophiles which are not known to form bridged intermediates attack at the exocyclic double bond. In such cases the energy of the endocyclic homoallylic, non-classical carbonium ion formed may be the most significant factor. Cycloaddition reactions can be distinguished in the same manner as the electrophilic additions. Concerted cycloaddition reactions attack at the endo double bond and two-step or highly asymmetrical cycloadditions react at the exo double bond. A brief discussion is also presented on the possible equilibriums and rearrangements which could accompany these reactions.

Library of Congress Subject Headings

Chemical reactions.
Addition reactions.



Number of Pages



South Dakota State University