Reactions of fatty materials with oxygen. XVII. Some observations on the secondary products of autoxidation of methyl oleate

Summary Methyl oleate, autoxidized for short and long periods of time, has been fractionated with urea. Up to a peroxide content of about 15% the autoxidation mixture can be cleanly separated into a peroxide concentrate containing 90% peroxide and unoxidized methyl oleate. From about 15% peroxide to the maximum peroxide content (35–40%) concentration to only about 70% peroxide can be obtained, and the remaining material is largely a mixture of oxygenated compounds and residual methyl oleate. If the autoxidation is conducted beyond the peak value in peroxide content, little, if any, concentration of peroxide can be obtained. Also, beyond the peak in peroxide value and in the range of 30–20% peroxide, methyl oleate is substantially absent and the autoxidation mixture consists almost entirely of oxygenated compounds containing only one functional group in the chain. Evidence is presented which shows that in the autoxidation of methyl oleate substantially all of it undergoes single attack by oxygen (or peroxides) before any significant quantity of multiple attack occurs. α,β‐Unsaturated carbonyl compounds are among the important secondary products of autoxidation.