Thermal reactions of methyl linoleate. III. Characterization of C18 cyclic esters

This third paper presents the isolation and characterization of nonaromatic cyclic monomers formed from the heated linoleate. The esters were isolated by a series of column chromatographic separations, followed by repeated gas chromatography to obtain fractions containing C(18) cyclic esters. Characterization of the esters was achieved by use of infrared, NMR, mass spectroscopy, and standard chemical analyses. Also characterized were the isomers found in a complex mixture of cyclic monomers which had been partially separated by column chromatography. Use of both physical and chemical methods of analyses permitted characterization of the mixture of isomers without their having been separated from each other.