At least three plausible mechanisms for the Elbs reaction have been suggested. The first mechanism, suggested by Fieser, begins with a heat-induced cyclisation of the benzophenone, followed by a [[Sigmatropic reaction#%5B1,3%5D-shifts|[1,3]-hydride shift]] to give the compound . A dehydration reaction then affords the polyaromatic.
Alternatively, in the second mechanism, due to Cook, the methylated aromatic compound instead first undergoes a tautomerization followed by an electrocyclic reaction to give the same intermediate, which then similarly undergoes a [1,3]-hydride shift and dehydration.
A third mechanism has also been proposed, involving pyrolytic radical generation.