MqnD catalyzes the conversion of cyclic dehypoxanthine futalosine () to 5,8-dihydroxy-2-naphthoic acid () and an uncharacterized product. This study describes a chemoenzymatic synthesis of . This synthesis achieved a 2-fold yield enhancement by using titanium(III) citrate as the reducing agent and another 5-fold yield enhancement using a fluorinated analogue of dehypoxanthine futalosine () that was converted to by an ipso substitution mechanism. This synthetic route enabled the synthesis of in sufficient quantity to identify the second reaction product and to determine that the MqnD-catalyzed reaction proceeds by a hemiacetal ring opening-tautomerization-retroaldol sequence.