Bioreduction of substituted α-tetralones promoted by Daucus carota root

The bioreduction of a series of substituted α-tetralones, carried out using Daucus carota root (carrot), afforded the corresponding homochiral α-tetralols in variable conversions (9 to 90%) and excellent enantiomeric excesses. Two of the assayed α-tetralones were resistant to the bioreduction conditions. The absolute configurations of four α-tetralols were assigned as being (S), by comparison to the (S)-enantiomers obtained by kinetic resolution promoted by CALB-catalysed acetylation. Additionally, the new 5-methoxy-6-methyl-1-tetralone was synthesized in seven steps from 3-methylsalicylic acid. (author)