| Abstract
| - The four conformations of β-caryophyllene (αα, αβ, βα, and ββ) were investigated ab initio at the6-31G*/HF and MP2 levels and additionally with density functional methods (B3LYP/6-31G*), asit concerns their relative thermodynamic stabilities. The αα is predicted to be the most stablegeometry, in agreement with low-temperature NMR measurements. In the case of 6-hydroxycaryophyllene, the αα is still the most stable conformation when the configuration at C-6 is S, butwhen the configuration is reversed to R the ββ geometry becomes the most stable one. This isagain in agreement with NMR data. On the other hand, for both molecules the AM1 semiempiricalmodel Hamiltonian fails to predict the αα as a low-energy geometry, mainly due to an incorrectdescription of the cyclobutane ring puckering. The interconversion paths among the different minimaare also analyzed and discussed. The solvent effect (either chloroform or water) on the stability ofthe different conformers of β-caryophyllene and 6-hydroxycaryophyllene was studied in thepolarizable continuum model framework.
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