Chloroperoxidase catalysed oxidation of benzyl alcohol using tert-butyl hydroperoxide oxidant in organic media

The quantitative oxidation of benzyl alcohol to benzaldehyde using the enzyme chloroperoxidase (CPO) from Caldariomyces fumago as catalyst and tert-butyl hydroperoxide (t-BuOOH) as a cosubstrate for the enzyme, in organic solvent is demonstrated. The enzymatic transformation of primary alcohols to aldehydes has not previously been shown in predominantly organic solvent using CPO, and in aqueous media, has only been reported to have been effected in moderate yields. A simple procedure for this transformation was carried out using 10 μmol each of benzyl alcohol and t-BuOOH dissolved in water-saturated isooctane (1.5 ml), 0.5 μl CPO solution (10 units) in pH 4.0 acetate buffer. The reaction rates obtained in organic media were similar to that obtained in aqueous media, the enzyme was found to be significantly stabilised towards peroxide dependent inactivation and no continuous addition of the peroxide was necessary.