Catalytic Transfer Hydrogenation of Castor Oil

The main thickening agent or soap in multipurpose grease, lithium 12-hydroxystearate, is a chemical commodity for the auto industry. This compound is obtained from castor oil via a series of chemical transformations. The first step, hydrogenation of castor oil, has been developed into a laboratory experiment for second-year undergraduate organic chemistry. Students are introduced to catalytic transfer hydrogenation (CTH) as a method to reduce a carbon–carbon double bond in ricinoleic acid, the main fatty acid in castor oil. Students perform a comparative analysis based on calculation of several green metrics: atom economy, E factor, reaction mass efficiency, CO 2 emissions, and costs. The product, hydrogenated castor oil, is characterized by several techniques: 1 H NMR and IR spectroscopy, and melting point.