Nearly all monomers examined (oxanorbornenes and norbornenes) with predicted RSEs of > 15 kcal/mol exhibited high reactivity in polymerization and were consumed in 1 h. The two monocyclic alkenes, cyclohexene (COH) and cyclooctene (COE), have predicted ring strain energies of 2.53 kcal/mol and 9.69 kcal/mol, respectively. These are close to the experimental RSE of 2.5 and 7.4 kcal/mol for COH and COE . Consistent with expectation, the cyclooctene is essentially completely consumed at 1 h 65 , while cyclohexene is not consumed under the polymerization conditions (minor evaporation was noted in the 1 H NMR spectrum, Figure & S25). The rapid consumption of COE with its lower RSE relative to a derivative such as DMONa which is not fully consumed after 24 h even though it has high RSE demonstrates that many factors influence polymerization rate. While the RSE is a key factor in polymerization, it is not the only consideration as solvent, monomer stereochemistry, steric effect will influence the outcome.