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

Abstract

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