Chemoenzymatic resolution of racemic Wieland-Miescher and Hajos-Parrish ketones
2010
Janeczko, Tomasz | Dmochowska-Gładysz, Jadwiga | Kostrzewa-Susłow, Edyta
Enantiospecific microbial reduction of bicyclic ketones was described. Racemic Wieland-Miescher (1) and Hajos-Parrish (2) ketones were used as substrates. In a 4-h biotransformation of Hajos-Parrish ketone (2) using the strain of Didymosphaeria igniaria an optically pure ketone (R)-2 was obtained, whereas the (S)-2 ketone underwent reduction to (4aS,5S)-4 alcohol with 100% of enantiomeric excess and with over 60% of diastereoisomeric excess. Jones oxidation of the alcohol obtained in the biotransformation gave an optically pure ketone (S)-2. Enzymatic system of Coryneum betulinum reduced the (R)-2 ketone to (4aR,5S)-4 alcohol with a high enantiomerical purity in a 6-day reaction. Wieland-Miescher (1) ketone was transformed by these microorganisms in an analogous way, but the reaction times were longer.
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