caa a22 4500 465822592 CHVBK 20180323112139.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF00173723 doi (NATIONALLICENCE)springer-10.1007/BF00173723 Asymmetric microbial reduction of ethyl and isoprophyl α,1,3-trioxo-2-isoindolinebutyrate [Elektronische Daten] [Peter Matzinger, Beat Wirz, Hans Leuenberger] Summary: Microorganisms are capable of the asymmetric reduction of various types of ketones. From a limited screening with 103 selected microbial strains two have been chosen which reduce ethyl and isopropyl α,1,3-trioxo-2-isoindolinebutyrate (1a and 1b) stereoselectively. The optically active products ethyl and isopropyl α-hydroxy-1,3-dioxo-2-isoindoline butyrate (2a and 2b) are useful precursors of the cerebral insufficiency improver hydroxy-aniracetam. Up to 3% of substrates 1a or 1b can be added in the reaction medium and converted by Candida parapsilosis. The isolated (R)-enantiomers of the product alcohols 2a and 2b show an enantiomeric excess (ee) of 98%-99%. The process was successfully tested on a 200-1 scale, the transformation rate being 0.83 g/1 per day and the yield of isolated product 72%. With Torulopsis magnoliae (S)-enantiomers of the products 2a and 2b were formed with an ee of 97%-99%. Springer-Verlag, 1990 Matzinger Peter Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut Wirz Beat Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut Leuenberger Hans Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut Applied Microbiology and Biotechnology Springer-Verlag 32/5(1990-02-01), 533-537 0175-7598 32:5<533 1990 32 253 https://doi.org/10.1007/BF00173723 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00173723 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Matzinger Peter Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut NATIONALLICENCE 700 1- Wirz Beat Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut NATIONALLICENCE 700 1- Leuenberger Hans Central Research Units, F. Hoffmann-La Roche AG, Basle, Switzerland aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer-Verlag 32/5(1990-02-01), 533-537 0175-7598 32:5<533 1990 32 253 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer