Kinetics of the epoxidation of geraniol and model systems by dimethyldioxirane

The mono-epoxidation of geraniol by dimethyldioxirane was carried out in various solvents. In all cases, the product ratios for the 2,3 and 6,7 mono-epoxides were in agreement with literature values. Kinetic studies were carried out at 23 degreesC in the following dried solvent systems: acetone (k(2) = 1.49 M-1 s(-1)), carbon tetrachloride/acetone (9/1, k(2)=2.19 M-1 s(-1)), and methanol/acetone (9/1, k(2) = 17 M-1 s(-1)). Individual k(2) values were calculated for epoxidation of the 2,3 and 6,7 positions in geraniol. The nonconjugated diene system was modeled employing two simple independent alkenes: 2-methyl-2-pentene and 3-methyl-2-buten-1-ol by determining the respective k(2) values for epoxidation in various solvents. The kinetic results for each independent alkene showed that the relative reactivity of the two epoxidation sites in geraniol as a function of solvent was not simply a summation of the independent alkene systems.