Preparation and Evaluation of a Series of Alpha-Hydroxy Ethers from 9,10-Epoxystearates

Authors: Moser, Bryan; Erhan, Sevim

Submitted to: European Journal of Lipid Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/26/2007
Publication Date: 3/13/2007
Citation: Moser, B.R., Erhan, S.Z. 2007. Preparation and evaluation of a series of alpha-hydroxy ethers from 9,10-epoxystearates. European Journal of Lipid Science and Technology. 109:206-213.

Interpretive Summary: A series of organic compounds have been prepared from the readily available vegetable oil based materials, oleic acid. We have studied these materials with respect to their low temperature performance through determination of both their cloud and pour points. These are important properties for the development of cold flow additives for biodiesel, which suffers from relatively poor cold weather operability in comparison to petrodiesel. This research benefits the vegetable oil industry by helping to open markets for vegetable oil-based materials for use in biodiesel fuel, another vegetable oil product.

Technical Abstract: Several novel alpha-hydroxy ethers were synthesized by treatment of isobutyl 9,10-epoxystearate with a number of aliphatic alcohols in the presence of acid catalyst in good overall yield from oleic acid. The materials low temperature behavior was analyzed through cloud point and pour point determination. The most desirable derivative was isobutyl 9(10)-(2-ethylhexoxy)-10(9)-hydroxystearate as compared to other alpha-hydroxy ethers. Therefore, additional alpha-hydroxy-2-ethylhexyl ethers were produced from alkyl 9,10-epoxystearates (butyl, hexyl, 2-methylpentyl, 2-ethylbutyl, 2-ethylhexyl) to explore the effect of head group on the low temperature performance of the optimized 2-ethylhexyl ether moiety. The most bulky head group, 2-ethylhexyl, was found to impart the most favorable low temperature performance, which yielded a cloud point of -26 deg C and a pour point of -29 deg C for 2-ethylhexyl 9(10)-(2-ethylhexoxy)-10(9)-hydroxystearate. An improved synthesis of 2-ethylhexyl 9(10)-(2-ethylhexoxy)-10(9)-hydroxystearate was then developed from 9,10-epoxystearic acid. Lastly, in an effort to optimize yield, sulfuric acid at 10 mol% was found to be the most effective acid catalyst in the conversion of epoxides to alpha-hydroxy ethers.