Selective oxidation reactions of natural compounds with hydrogen peroxide mediated by methyltrioxorhenium

Abstract

We have investigated the oxidative behaviour of natural compounds such as methyl abietate (1), farnesyl acetate (2), a-ionone (3), β-ionone (4), methyl linolelaidate (5), methyl linolenate (6) and bergamottin (7) with the oxidant system methyltrioxo-rhenium/ H2O2/pyridine. The reactions, performed in CH2Cl2/H2O at 25 °C, have shown good regioand stereoselectivity. The oxidation products were isolated by HPLC or silica gel chromatography and characterized by MS(EI), 1H-, 13C-NMR, APT, gCOSY, HSQC, TOCSY and NOESY measurements. The selectivity seems to be controlled by the nucleophilicity of double bonds and by stereoelectronic and steric effects. © 2013 by the authors.