3.1 Characterization of MO and EMO with1H-NMR
1H NMR spectra of OA, MO and its epoxide (EMO) are shown in Fig. 1 . Esterification of OA leads to the formation of MO which is supported by the appearance of a signal at 3.63 ppm (Fig. 1 ) corresponding to methoxy group (-OCH3) in MO. The same signal was not originally present in the proton NMR spectra of OA. The signal appearing at 5.3 ppm is due to the presence of the unsaturation (-CH=CH-) in the hydrocarbon chain of OA as well as MO. Accordingly, the formation of EMO from MO was confirmed by the appearance of signal at 2.9 ppm corresponding to the epoxy protons and disappearance of signal at 5.3 ppm due to the unsaturated protons (Fig. 1 ).
1H-1H COSY spectrum of epoxy methyl oleate and coupling pattern also shows the formation of EMO. Methoxy protons do not show any coupling and appear as a singlet at δ3.57 ppm. Further, Epoxide ring protons shows coupling with the adjacent protons, therefore, appeared as a multiplet at δ~ 2.81 ppm ( Fig. 1s, supporting information).
Protons α to the carbonyl group shows coupling with protonsβ to carbonyl group and appear as a triplet at δ 2.23-2.19 ppm. Terminal methyl group also shows coupling with adjacent -CH2- (methylene protons) and found resonating as a triplet at δ 0.84-0.79 ppm.
All these couplings show confination of epoxy methyl oleate structure and splitting pattern.
Characterization of methyl oleate by 1H NMR (400 MHz, CDCl3) δ (ppm) : 5.39 - 5.30 (m, 2H, -CH =CH -), 3.66 (s, 3H -OCH3 ), 2.32-2.28 (t, 3H -CH2 -CO-), 2.07-1.98 (m, 4H, -CH2 CH=CHCH2 -), 1.63-1.58 (m, 2H, -CH2 -CH2-CO-), 1.35- 1.25 (m, 20H, (CH 2)n-), 0.89-0.86 (t, 3H, -CH2-CH 3) as shown in