Reduction of acetophenones with methyl fluorines and a bulky group on the aromatic ring using microorganisms and related enzymes

Abstract Whole-cell yeasts and mold-catalyzed reduction of two fluorinated acetophenone derivatives with very bulky substituents on ortho position of aromatic ring, (±)-1′-(2 -tert -butyl-2-methyl-1,3-benzodioxol-4-yl)-2′,2′-difluoroethanone and (±)-1′-(2- tert -butyl-2-methyl-1,3-benzodioxol-4-yl)-2′,2′,2′-trifluoroethanone were examined. On the former substrate, Geotrichum candidum NBRC 5767 showed high re -facially selective attack of hydride, while with Pichia angusta JCM 3620, complementary si -facially selective attack proceeded. G. candidum NBRC 5767 was revealed to be potent biocatalyst which provides (1′ S )-alcohols from both substrates in a highly facially selective manner. Some unknown reductases were suggested responsible for those reductions, other than so far having been reported acetophenone reductase and trifluoromethyl ketone reductase from G. candidum , comparing the results obtained by applying those enzymes.