1978 年 27 巻 5 号 p. 286-293
The catalytic addition reaction of maleic anhydride to safflower fatty acids or their methyl esters was investigated. It is found that the synthetic silica-alumina composed of 70% of SiO2 and 29% of Al2O3 has high catalytic activity for the addition reaction of maleic anhydride to safflower fatty acid methyl esters and that the addition to safflower fatty acids is also easily carried out by continuously passing the mixed solution of maleic anhydride and safflower fatty acids over a catalyst having phosphoric acid deposited on the silica-alumina as a carrier. In the addition reaction by using the silica-alumina, it is observed that maleic anhydride is added mainly to octadecadienoic acids, being main component of safflower fatty acids and hardly to octadecenoic acids.
Moreover, the adduct separated by column chromatography was known to be predominantly consisted of the fatty acids and maleic anhydride at a proportion of 1 : 1 and to have a cyclohexene ring structure by IR, NMR and MS spectral analysis. Then, the addition reaction was considered to be based on the Diels-Alder addition reaction of maleic anhydride to conjugated octadecadienoic acids produced with the isomerization of linoleic acid by the catalyst.