107. Preparative Asymmetric Reduction of 3-Ketobutyrate and -valerate by Suspended Cells of Thermophilic Bacteria (Thermoanaerobium brockii) in Ordinary Laboratory Equipment

Article abstract of DOI:10.1002/hlca.19850680420

The thermophilic and anaerobic bacteria specified in the title are isolated on a 0.8 kg scale by tangential flow filtration and centrifugation from a 300-l bioreactor.The microorganisms are stored in a freezer (-20 deg) and used, analogously to baker's yeast, for asymmetric reductions.Thus, ethyl 3-ketovalerate (4.3 g/l (H2O) is converted in 40 percent yield to (S)-3-hydroxyvalerate (6), with an enantiomeric excess of 93 percent (24 h at 72 deg).