A mechanism for ring opening of amine 4 in pure MeOH was finally calculated (model "c"), modeled with three molecules of methanol. The SN2-step and proton transfers all happened on a single energy surface with no formal intermediates along the route, an asynchronous concerted reaction (Def2-TZVPP basis). The calculated free energy barrier was 26.1 kcal/mol, similar in effect to the Li(THF)2 + model and leading to a similar rate of acceleration.