We are given four NMR spectra of a composite solution of Diels-Alder product of furan and maleic anhydride. On the earliest scan we only start with three signals and and by the last scan we see three new additional signals. We believe that the first three signals are the exo product, however we are stuck between two possible reasons as to why the signals form. Our first idea is that it is converting back into furan and maleic anhydride due to equilibrium, and this would be consistent with the three NMR signals that form. However, we know that there is also the endo form of the product as well. Our question is, is it possible we started with the endo and it's the exo form that's forming? Or do we start with exo and get our reactants again?
