Which cyclization(s)should occur with a decrease in pi-electron energy?

Question

Quizplus · Accepted Answer

Cyclization II involves the formation of a five-membered ring, which is thermodynamically favored due to the decrease in ring strain energy compared to larger rings. The formation of a five-membered ring also increases the stability of the pi-electron system by allowing for greater delocalization. The other cyclizations involve the formation of larger rings, which require more energy and are less stable. As a result, they are less likely to occur with a decrease in pi-electron energy.

Which Cyclization(s)should Occur with a Decrease in Pi-Electron Energy