An Experimental and Computational Approach to Defining Structure/Reactivity Relationships for Intramolecular Addition Reactions to Bicyclic Epoxonium Ions

In this manuscript we report that oxidative cleavage reactions can be used to form oxocarbenium
ions that react with pendent epoxides to form bicyclic epoxonium ions as an entry to the formation of cyclic
oligoether compounds. Bicyclic epoxonium ion structure was shown to have a dramatic impact on the ratio
of exo- to endo-cyclization reactions, with bicyclo[4.1.0] intermediates showing a strong preference for
endo-closures and bicyclo[3.1.0] intermediates showing a preference for exo-closures. Computational studies
on the structures and energetics of the transition states using the B3LYP/6-31G(d) method provide
substantial insight into the origins of this selectivity.