Microbiological reductions of chromen-4-one derivatives

From the microbiological reductions of 2-acetyl or 2-benzoylchromen-4-one b oth enantiomers of the corresponding alcohols were obtained with high enant iomeric excess. The absolute configurations were determined directly by an X-ray structural determination. The results obtained showed that for most o f the microorganisms tested, an inversion of the configuration of the alcoh ol occurred with the change of the substituent (methyl to phenyl group) in position 2, but also with the presence of a bromine atom in position 6 of t he aromatic ring, positioned quite far from the prochiral centre. (C) 2000 Elsevier Science Ltd. All rights reserved.