the authors were able to experimentally work out a rate law at 261.2 k for the reaction of 1,2-dimethylidenecyclohexane with sulfur dioxide to give the corresponding sulfolene. the reaction was first order in 1,2-dimethylidenecyclohexane but second order in sulfur dioxide (see below). this confirmed a prediction of theoretical chemists based on high-level "ab initio" quantum calculations. using computational methods, the authors proposed a transition structure for the cheletropic reaction of 1,2-dimethylidenecyclohexane with sulfur dioxide (see figure at right). the reaction is second order in sulfur dioxide because another molecule of sulfur dioxide likely binds to the transition state to help stabilize it. similar results were found in an 1995 study by suarez, sordo, and sordo which used "ab initio" calculations to study the kinetic and thermodynamic control of the reaction of sulfur dioxide with 1,3-dienes.