A Green Two-Step Preparation of Dimmer Acids

A two-step preparation of dimmer acids was studied starting from linoleic acid in moderate condition. The isomerization from linoleic acid to conjugated linoleic acid(CLA) is the controlling step in the synthesis of dimmer acids, usually performed under very high temperature and pressure. Lipoxygenase was used here to prepare linoleic hydroperoxide(HPOD), and then hydroxy conjugated linoleic acid(HOD) was easily obtained through reducing HPOD with Na₂SO₃ in alcohol and water solution at room temperature. The second step was to give dimmer acids using HOD and oleate acid catalyzed by AlCl₃ . The reaction parameters such as preparation and loading of the catalyst, reaction temperature and time were investigated.