Reactions of Tertiary Butyl Hypochlorite with Vegetable Oils and their Derivatives. IV.² Conversion of Alkyl Oleates and Methyl Linoleate to Derivatives of Ketostearic Acids³

Abstract

Alkyl alkoxychlorostearates have been prepared by the reaction of aa alkyl oleate with t-butyl hypochlorite in presence of 9-( 10)-Ketostearic Methyl dimethoxydichlorostearate has been prepared by the an alcohol. acid was obtained by saponification of the alkyl ketostearate. same reaction.These compounds are decomposed by heat with the formation of alkyl 9-( 10)-ketostearate, It yields a methyl diketostearate on pyrolysis. Price and Griffith4 have described the preparation of methyl methoxychlorostearate by chlorination of methyl oleate in methanol solution. We have found that this compound, and other alkoxy chlorostearates, may be obtained from the reaction of methyl oleate with t-butyl hypochlorite in the presence of the corresponding alcohol. This method offers the advantages of rapidity and of minimizing the formation of dichlorostearate. It has been applied to lower olefinic compounds by Harford6 and by Hennion and co-workes6During attempts to purify methyl methoxychlorostearate by distillation, the sensitivity of this compound to heat was observed. A solid product was obtained which was identified as a niixture of methyl 9-and 10-ketostearates. A study of the reaction conditions showed that this conversion could be accomplished in 70% yield by pyrolysis of methyl methoxychlorostearate a t 285-290' and a pressure of 100 mm. The corresponding niixture of 9-and 10-ketostearic acids was readily obtained by saponification of the ester.Although detailed study of the reaction niechanism was beyond the scope of this investigation, the apparent course of the reaction is indicated by the following scheme, in which R and R' represent the remaining parts of the methyl oleate molecule H H

Reactions of the Hydrocarbon Chain of Fatty Acids.

“…A number of 9(10)-alkoxy-10(9)-chlorooctadecanoates have been produced by the reaction of unsaturated fatty acid esters (oleic, elaidic, linoleic, m- 13-docosenoic) with alkyl hypochlorites (185,457,547). The methyl, ethyl, propyl, isopropyl, butyl, íerí-butyl, and pentyl derivatives were included.…”