Thus famously wrote Woodward and Hoffmann (WH) in their classic monograph about the conservation of orbital symmetry in pericyclic reactions. But they also note that the “fantastic” hydrocarbon (number 85 in their review) shown below presents a situation of great interest in having a half life of ~30 minutes at 353K (a free energy barrier of ~ 26.2 kcal/mol). Here I investigate if it might actually be such a violation. (more…)