In order to produce a broad range of syn-sesquinorbornene disulfones, (Z)-1,2-bis(phenylsulfonyI)ethylene was added in Diels-Alder fashion (high-pressure conditions) to tricyclo[5.2.1.0(2.6)]deca-2,5,8-trienes carrying isopropylidene or spirocyclopropane subunits at one or two sites. The central double bond in these adducts was then regiospecifically reduced with diimide, epoxidized with MCPBA, or cyclopropanated by [3 + 2] cycloaddition with diazomethane and subsequent photoinduced nitrogen extrusion. Each product in ah-three series was subjected to X-ray crystallographic analysis in order to quantify in the solid state the distance which each endo alpha-sulfonyl proton is required to traverse during dyotropic migration to the proximal norbornene double bond. The kinetics of these isomerizations were also determined, a relative reactivity scale was realized, and the values of k(ref) at 160 degrees C were found not to correlate well with the average distance across the intracavity gap. Although proximity of the reaction centers is clearly a prerequisite for smooth operation of the dyotropic shifts, modulation of this distance is not the sole contributor to reaction rate. Rather, the data are in agreement with the working hypothesis that various levels of steric compression within these disulfones facilitate passage over the relevant transition state to a greater or lesser degree depending on the magnitude of these nonbonded interactions.