Oxidative cyclization of linoleic acid in the presence of hydrogen peroxide and phosphotungstic acid

The synthesis of THF and tetrahydro-2H-pyrane is of interest due to the applications of such molecules as antitumour, pesticidal, antiprotozoal and antimicrobial agents for instance. Here, an original approach was performed to prepare these derivatives starting from linoleic acid in the presence of hydrogen peroxide and phosphotungstic acid in the absence of a phase transfer agent. A maximum cyclic compounds yield of 99 % was obtained under mild conditions of temperature. A heterogeneous catalyst was synthesized by exchanging proton by Cs to obtain Cs2.3H0.7PW12O40, that was recycled up to 3 cycles. It is one of the best yield to these products observed in the literature from fatty acids.