Dual catalytic role of molybdate ions for direct conversion of photo-oxidized fatty acid methyl esters into keto or hydroxy derivatives

Overview & Synopsis

An organosoluble ammonium molybdate salt catalytically converts allylic hydroperoxides of fatty acid methyl esters with good selectivities into either their corresponding alcohols or enones depending on the reaction conditions. Whereas a gentle heating of methyl oleate hydroperoxides in toluene at 80 °C mainly provides the enone in a 83/17 ratio, presence of triethylamine at 40 °C reverses this ratio to 7/93 in favor of the alcohol. Extension of the reaction scope to other alkenes like cyclohexene, cyclooctene, α- and β-pinenes, β-citronellol, and 2-octene shows the wide potential applications of the process which lead to relevant oxygenated building blocks, especially oils as a possible alternative of castor oil.