The above is one of the final reactions in the synthesis of an enantiospecifically labeled fatty acid. It involves a reduction with Lindlar's Catalyst in the presence of deuterium, an isotope of hydrogen. Lindlar's Catalyst (powdered barium sulfate coated with Pd, poisoned with quinoline) converts an alkyne to a cis-alkene, as seen in the reaction above. The article I looked at focused on pheromone biosynthesis in S. isatideus and the role stereochemistry played. Article Link.