Methyl oleate
Thermal oxidation caused a 90% decrease in the olefin13C NMR signal (Figure 6 ) of methyl oleate. Olefinic carbons were transformed largely into epoxide, trans (59 ppm) and cis (57 ppm) carbons along with ester, carboxyl and ketone carbons (Table 1 ). Formation of these higher oxidized species also caused an increase in methylene carbons. Thus, one of the olefin carbons was reduced. For example, the CH2 next to the internal ketone (211 and 42 ppm signals).
Classical reaction schemes for methyloleate oxidation involve unsaturated hydroperoxy species. Molecular structures with double bonds near carbons containing oxygen (peroxy, epoxide or alcohol) can be ruled out based on long-range (HMBC)13C-1H NMR experiments (vide sotto).
DOSY shows untreated methyl oleate with D = (3.5 ± 0.1) x 10-10 m2/s (Table 2 andFigure S 8 ). After oxidation, the small olefinic group (1H signal at 5.1 ppm) of unreacted methyl-oleate exhibits D = (1.2 ± 0.05) x 10-10m2/s while the abundant newly formed epoxide species (signal at 2.6 ppm) gives D = (1.0 ± 0.05) x 10-10m2/s, Figure 7 . The slowest moving species D = 0.7 x 10-10 m2/s is associated with the methoxy signal (at 3.2 ppm). However, careful inspection shows a 2-component fit is required (Figures S9 and S10 ), with the slowest component still being circa D = 0.7 x 10-10m2/s. This component is five times slower than untreated methyl oleate, but only two times slower than unreacted methyl oleate. Thus, as seen above for trans-7-tetradecene, the epoxide (oxidation product) diffuses somewhat slower than the non-oxidized molecule. This is attributed to increased polarity rather than oligomerization.