Chloroperoxidase-catalyzed oxidation of 5-hydroxymethylfurfural

Chloroperoxidase (CPO) catalyzes the oxidation of 5-hydroxymethylfurfural (HMF) with hydrogen peroxide as the oxidant. The reaction proceeds with 60-74% selectivity to furan-2,5-dicarboxaldehyde (FDC). The main byproduct is 5-hydroxymethyl-2-furancarboxylic acid (HFCA); a minor amount of 5-formylfuran-2-carboxylic acid (FFCA) was also detected. When (H2O2)-O-18 was used a virtually quantitative incorporation of O-18 was observed in the HFCA product, whereas no O-18 was incorporated from (H2O)-O-18. Hence, the CPO-catalyzed oxidation of aldehydes to acids proceeds with direct oxygen transfer from the iron-ore complex of CPO. Controlling the H2O2-addition with a H2O2-stat facilitated the reaction procedure and a conversion of 87% of HMF was reached within 21 min.