alpha-Pinene isomerization starts with the formation of the pinanyl carbocation, which then undergoes rearrangement into two different isomers. One isomer yields monocyclic rings as final products, such as limonene, alpha-terpinene, and terpinolene while the other isomer yields bicyclic compounds, including camphene. In this Letter, a computational study is carried out in order to find the optimal temperature and solvent for the promotion of the second path considering that the bicyclical compounds are of greater economical interest. The energies of formation of the carbocations at different temperatures were calculated in vacuum and in solvents using the PBEPBE/6-31+G(d,p) model chemistry. (C) 2012 Elsevier B.V. All rights reserved.