Computational Exploration of the Thermal Rearrangement of Basketene: One Forbidden versus Two Allowed Pericyclic Reactions

The thermal rearrangement of basketene to Nenitzescu's hydrocarbon has been explored using density functional theory (M06-2X and omega B97X-D) and DLPNO-CCSD(T) quantum mechanics. Both the sequential thermally allowed retro Diels-Alder followed by Cope rearrangement and the thermally forbidden retro-[2 + 2] cycloaddition were studied. The controlling role of orbital symmetry rather than reaction thermodynamics is demonstrated.

Automated summary

In this study, the thermal rearrangement of basketene to Nenitzescu's hydrocarbon was investigated using quantum mechanics. Both the sequential retro-Diels-Alder followed by Cope rearrangement and the thermally forbidden retro-[2 + 2] cycloaddition were studied, and the controlling role of orbital symmetry was demonstrated.