Synthesis of Long Chain Unsaturated-alpha,omega-Dicarboxylic Acids from Renewable Materials via Olefin Metathesis

Authors: Ngo, Helen; Foglia, Thomas

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2007
Publication Date: 8/1/2007
Citation: Ngo, H., Foglia, T.A. 2007. Synthesis of Long Chain Unsaturated-alpha,omega-Dicarboxylic Acids from Renewable Materials via Olefin Metathesis. Journal of the American Oil Chemists' Society. 84:777-784.

Interpretive Summary: Unsaturated fatty acids present in fats and oils can be converted into long-chain diacids, chemical intermediates for the production of polymers. Present chemical methods for making these diacids use either hazardous reagents or are environmentally unfriendly while fermentative routes are costly and limited in the types of diacids produced. In this paper, we describe a catalytic approach to the direct production of such diacids from common oils and fats. The process is environmentally benign since the method does not require solvents or other reagents. The method uses only a very small amount of catalyst to convert the vegetable oil- and animal fat-derived fatty acids into diacid products in high conversions and high yields. This process represents an effective and efficient route to the synthesis of these dicarboxylic acids, which are potentially useful intermediates for the production of biodegradable polyesters and polyamides.

Technical Abstract: The self-metathesis reaction of soy, rapeseed, tall, and linseed oil fatty acids was investigated for the synthesis of symmetrical long-chain unsaturated-alpha,omega-dicarboxylic acids. The metathesis reactions were carried out in the presence of a Grubbs catalyst under solvent-free conditions at a catalyst loading of 0.01 mol% to fatty acid substrate at 50°C. Under these conditions, the conversions of starting unsaturated acids to metathesis products were >80% and the isolated yields of unsaturated dicarboxylic acid products were >70% of theoretical. This approach represents an effective and efficient route for the synthesis of these potentially useful dicarboxylic acids since they can serve as important intermediates in the production of several materials such as biodegradable polymers.