benzene is actually much stable than we would expect from the simple resonance-delocalized picture. both the kekuie structure and the resonance-delocalized picture show that benzene is a cyclic conjugated triene. we might expect benzene to undergo the typical rections of polyenrs. in fact , its reactions are quite unusual.for example, an alkene decolorizes potassium permanganate by reacting to from a glycol.the purple permanganate color disappears, and a precipitate of manganese dioxide froms. when permanganate is added to benzene, however, no reaction occurs