Laccase from Basidiomycetous Fungus Catalyzes the Synthesis of Substituted 5-Deaza-10-oxaflavins via a Domino Reaction

The present investigation provides a simple and convenient route for the synthesis of substituted 5-deaza-10-oxaflavins owing to their importance as probable redox coenzymes. The reaction of alpha,beta-unsaturated derivatives of barbituric acid and di-medone with catechol or 1,4-hydroquinones was catalyzed using laccase in aqueous medium. Quinones, generated in situ by the oxidation of the corresponding catechol or 1,4-hydroquinones., underwent a domino reaction with chalcones to produce 5-deaza-10-oxaflavins and tetrahydroxanthen-1-ones.