Hydroxylation and Epoxidation of Rapeseed Oil Derivatives With Subsequent Pyrolysis and Ammonolysis

Abstract

A method was developed to follow the hydroxylation of rapeseed oil and erucic acid derivatives with peracetic acid. Peracetic acid prepared insitu was found to be equally as effective as the preformed acid in hydroxylation of methyl erucate. Among the compounds synthesized were ethyl 13,14-dihydroxybehenate, methyl 13,14-oxidoerucate, ethyl 13,14-diacetoxybehenate, and methyl 13,14(14,13)-hydroxyacetoxybehenate which were subsequently pyrolyzed at approximately 300 °C with p-toluenesulphonic acid as catalyst. The first compound yielded mainly the corresponding ketone with a small amount of the oxido derivative, the chief product of the second compound was also the ketone with some unsaturated material, the third compound yielded 43% of the diene, while the last one yielded 60%. Ammonolysis of the oxido compound or the bromohydrin to yield the corresponding aminohydroxy derivative under pressure with liquid ammonia and ammonium bromide was unsuccessful. A new compound oxidoerucamide, m.p.101.5°, was synthesized.

<b>Ethylmethyldioxirane epoxidation of <i>Plukenetia cononophora</i> oil</b>

“…The epoxidised oil in addition to the above showed a distinct doublet absorption at 823 cm -1 characteristic of the C-O-C oxirane stretch usually observed in the naturally epoxidised vegetable oils [15]. The absence of hydroxyl band in the IR spectra of the epoxidised PKCP oil indicates the superiority of the dioxirane epoxidation of triglyceride over the peracid epoxidation which has been noted to cause oxirane ring opening to the diols [6,16].…”

“…Furthermore the epoxides prepared by these methods must be instantly separated from the acids to avoid the oxirane ring opening which leads to lower oxirane value. It has also been generally observed that peracid oxidation of unsaturated vegetable oils do not appear to go to completion [4][5][6]. To circumvent these problems Sonnet and Foglia [7] suggested the use of dioxiranes.…”