New and efficient syntheses of hydroxytyrosol and its lipophilic derivatives

Abstract

New and efficient oxidative procedures to synthesize hydroxytyrosol and its lipophilic derivatives are described. Starting materials are available and natural compounds such as tyrosol and homovanillyl alcohol. The oxidants of choice are both homogeneous and heterogeneous 2-iodoxybenzoic acid (IBX and IBX-polystyrene) able to perform the aromatic hydroxylation and the oxidative demethylation of phenolic compounds with a chemo and regioselectivity similar to that of the polyphenol oxidase and cytochrome P450. The reactions proceed quickly and the final products are isolated in good yields and high purity. After the first oxidation, IBX-polystyrene is recovered by simple filtration, regenerated and reused for more cycles of oxidation reactions without loss of efficiency