METATHESIS OF UNSATURATED FATTY-ACID ESTERS AND FATTY OILS

Self-metathesis of unsaturated fatty acid esters provides a convenient route to unsaturated diesters which can be used as intermediates for the production of polymers and other useful chemical products such as civetone. Cross-metathesis reactions with lower alkenes result in medi um-chain fatty acid esters which are highly-demanded raw materials for the industrial production of surfactants. Cross-metathesis with ethen e (ethenolysis) gives compounds with terminal double bonds, having a b road range of applications. The metathesis of fats and oils proceeds i ntra- as well as intermolecularly. Ethenolysis of unsaturated fatty oi ls or triglycerides allows the transformation of long-chain fatty acid triglycerides into fatty oils of lower molecular weight. In recent ye ars, new catalyst systems have proven useful for the metathesis of uns aturated esters. Especially modified heterogeneous rhenium-based catal ysts have attracted much attention. Other catalyst systems have also a ppeared, to be of interest for these substrates, notably molybdenum-ba sed catalysts. Certain CO-photoreduced cyclopropane-treated supported MoO3 catalysts give interesting results as a possible alternative to t he promoted rhenium oxide catalysts, especially when supported on sili ca.