Asymmetric reduction and oxidation of aromatic ketones and alcohols using W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus

J Org Chem. 2007 Jan 5;72(1):30-4. doi: 10.1021/jo0616097.

Abstract

An enantioselective asymmetric reduction of phenyl ring-containing prochiral ketones to yield the corresponding optically active secondary alcohols was achieved with W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus (W110A TESADH) in Tris buffer using 2-propanol (30%, v/v) as cosolvent and cosubstrate. This concentration of 2-propanol was crucial not only to enhance the solubility of hydrophobic phenyl ring-containing substrates in the aqueous reaction medium, but also to shift the equilibrium in the reduction direction. The resulting alcohols have S-configuration, in agreement with Prelog's rule, in which the nicotinamide-adenine dinucleotide phosphate (NADPH) cofactor transfers its pro-R hydride to the re face of the ketone. A series of phenyl ring-containing ketones, such as 4-phenyl-2-butanone (1a) and 1-phenyl-1,3-butadione (2a), were reduced with good to excellent yields and high enantioselectivities. On the other hand, 1-phenyl-2-propanone (7a) was reduced with lower ee than 2-butanone derivatives. (R)-Alcohols, the anti-Prelog products, were obtained by enantiospecific oxidation of (S)-alcohols through oxidative kinetic resolution of the rac-alcohols using W110A TESADH in Tris buffer/acetone (90:10, v/v).

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alcohol Dehydrogenase / genetics
  • Alcohol Dehydrogenase / metabolism*
  • Alcohols / chemistry*
  • Alcohols / metabolism*
  • Chromatography, Gas
  • Ketones / chemistry*
  • Ketones / metabolism*
  • Molecular Structure
  • Oxidation-Reduction
  • Substrate Specificity
  • Thermoanaerobacter / enzymology
  • Tryptophan / genetics
  • Tryptophan / metabolism*

Substances

  • Alcohols
  • Ketones
  • Tryptophan
  • Alcohol Dehydrogenase