Biomimetic Asymmetric Synthesis of (R)-GTRI-02 and (3S,4R)-3,4-Dihydroxy-3,4-dihydronaphthalen-1(2H)-ones

The NADPH-dependent tetrahydroxynaphthalene reductase (T4HNR) from Magnaporthe grisea was used for the biomimetic synthesis of (R)-GTRI-02 by stereoselective reduction of 1-(3,6,8-trihydroxy-1-methylnaphthalen-2-yl)ethanone. This also led to the isolation of a (3S,4R)-cis-ketodiol formed by T4HNR-catalyzed reduction of the corresponding hydroxynaphthoquinone. Flaviolin and lawsone also reduced to corresponding cis-ketodiols in good yields.