Chemical conversion of plant oils by modern catalytic methods is believed vital for developing eco-friendly routes to various building blocks and fine chemicals. Therefore, we opted to test the quinoxaline-derived catalyst in Z-stereoretentive self-metathesis of oleic acid methyl ester (Z)-34, confronting it with the results obtained previously by Grubbs and Mauduit. It was found that Ru3 used in 0.1 mol% loading led to 50% conversion of methyl oleate (equilibrium) in less than one hour, thus being more effective than Ru2 and Ru5 (however, the specialised, sterically activated catalyst Ru6 was reported to achieve the equilibrium in even a shorter time and at lower loading: 15 min at 0.05 mol%). Importantly, products of this reactions-alkenes 35 and 36 obtained with high stereoselection (Z/E = 99:1) are known as valuable building blocks, being used inter alia in the synthesis of (Z)-Civetone (from diester 36), and various pheromones (from both 35 and 36). Catalyst Ru3 was tested in self-metathesis of oleic acid 37, and also in this case achieved an equilibrium with perfect Z-selectivity at only 0.25 mol% of catalyst loading within 1 h (Scheme 5A).