Synthesis of hydroxyfatty esters by sequential epoxidation-hydrogenolysis: Solvent effects

The tandem/sequential combination of epoxidation and hydrogenolysis for unsaturated fatty esters is not straightforward, due to incompatibility problems with the impurities present or generated in the used solvents. The chlorinated impurities in α,α,α-trifluorotoluene leads to the formation of important amounts of chlorohydrins by HCl formation in the hydrogenolysis step. The use of trifluoroethanol (TFE) in the epoxidation step produces trifluoroacetic acid traces by oxidation, responsible for the opening of the epoxide with water and TFE. The solvent of choice was finally isobutyl acetate, which gathers the required physicochemical properties, with 85 % yield of hydroxystearates from methyl oleate in a sequential process.This work was financially supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (project number RTI2018-093431-B-I00) and the Gobierno de Aragón (E37_20R group, co-financed with Feder 2014-2020 “Construyendo Europa desde Aragón”).Peer reviewe