| Abstract
| - This study concerns the autoxidation of one of the most used fragrances in daily life, linalool (3,7-dimethyl-1,6-octadien-3-ol). It reacts with O2 to form hydroperoxides, which are known to be important contact allergens.Pathways for hydroperoxide formation are investigated by means of quantum mechanical electronic structurecalculations. Optimized molecular geometries and harmonic vibrational frequencies are determined usingdensity functional theory (DFT). Insight into how the addition of O2 to linalool occurs is obtained by establishinga theoretical framework and systematically investigating three smaller systems: propene, 2-methyl-2-butene,and 2-methyl-2-pentene. 2-Methyl-2-pentene was chosen as a model system and used to compare with linalool.This theoretical study characterizes the linalool-O2 biradical intermediate state, which constitutes a branchingpoint for the further oxidation reactions pathways. Thus, the observed linalool oxidation product spectrum isdiscussed in terms of a direct reaction path, the ene-type mechanism, and the radical mechanism. The majorhydroperoxide found in experiments is 7-hydroperoxy-3,7-dimethyl-octa-1,5-diene-3-ol, and the calculatedresults support this finding.
|
