Weigh 125 mg of DHMF to a 4 mL glass vial, add 1 mL of solvent H2O, and then add standards. The conversion of the substrates and the concentrations of the products formed were calculated from the standard curves of the HPLC chromatograms. The calculated reaction parameters were the percent substrate conversion (mol/mol) and yield was calculated based on the external standard method in the HPLC.