Stereoselectivity of the Enzymatic Reduction of Aldehydic and Ketonic Carbonyl Groups in Planar Chiral Organomanganese Complexes |
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Authors: | Yoshimitsu Yamazaki Masami Uebayasi Jun-ichiro Someya Kuniaki Hosono |
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Affiliation: | Fermentation Research Institute, Agency of Industrial Science and Technology, Higashi 1-1-3, Tsukuba, Ibaraki 305, Japan |
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Abstract: | (±)-Tricarbonyl(η5-1-formyl-2-methylcyclopentadienyl)manganese (1) was optically resolved with horse liver alcohol dehydrogenase (HLADH) and two species of yeasts, Saccharomyces sp. H-1 and Rhodotorula rubra IFO 889. Usually, (1R)-1 was preferentially reduced to give (?)-alcohol 2 of ≥ 97% e.e. ? 84% e.e. Ketone analogue (±)-tricarbonyl(η5-1-acetyl-2-methylcyclopentadienyl)-manganese (4) was reduced by the yeasts. The major product by S. sp. H-1 was the (1S,2R,1′S)-(+)-alcohol (5) (≥ 98% e.e.) and the minor product, the (1R,2S,1′S)-(?)-alcohol (6) (86% e.e.). R. rubra gave only the latter alcohol (≥ 99 % e.e.). The Stereodifferentiation mechanism for these bioreductions is discussed in terms of the Prelog rule. The mechanism for HLADH reduction was examined with computer graphics. |
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Keywords: | nobiletin melanogenesis extracellular signal-regulated kinase (ERK) tyrosinase |
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