The formation of dihydronapthalenes containing a ketone functionality connected to the aliphatic part of the partially saturated 6-membered ring from thermal ringcontraction of 1H-2-benzo [c]oxocins reveals an efficient and convenient approach to access these structures, as they are a key structural motif in many bioactive molecules but are hard to synthesize by existing organic methods. . Therefore, we decided to also explore the generality of thermal ring contraction from 1H-2-benzo [c]oxocins to dihydronapthalene performed at higher temperatures (Table ). Besides the transformation from 13a to 13d (vide supra), all types of 8-membered 1H-2-benzo [c]oxocins functionalized with different substituents at the enol ether moiety (including alkyls, bulky groups and aromatic rings) readily convert to dihydronapthalenes upon prolonged heating to 120°C. As such, the transformation of 1H-2benzo [c]oxocins to dihydronaphthalenes provides a valuable new strategy to construct these skeletons, and this reaction is indeed quite general.