Synthesis and properties of methyl 9,12,15-octadecatrienoate geometric isomers

Abstract

The eight geometrically isomeric methyl 9,12,15-octadecatrienoates were prepared by using the Wittig reaction to couple cis- or trans-3-hexyenyltriphenylphosphonium bromide and methyl 12-oxo-cis- or trans-9-dodecenoate. Pairs of geometric triene isomers formed were separated by partial silver resin chromatography. Physical constants including melting points, percent trans by infrared, equivalent chain lengths (ECL), and 13C nuclear magnetic resonance (NMR) chemcial shifts are tabulated for the individual isomers. © 1982.