- Multiple Absolute Stereocontrol in Cascade Lactone Formation via Dynamic Kinetic Resolution Driven by the Asymmetric Transfer Hydrogenation of Keto Acids with Oxo-Tethered Ruthenium Catalysts
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A straightforward asymmetric construction of chiral fused γ- and δ-lactones containing multiple contiguous stereocenters was successfully developed by either (1) the dynamic kinetic resolution-asymmetric transfer hydrogenation (DKR-ATH) reaction using oxo
- Touge, Taichiro,Sakaguchi, Kazuhiko,Tamaki, Nao,Nara, Hideki,Yokozawa, Tohru,Matsumura, Kazuhiko,Kayaki, Yoshihito
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supporting information
p. 16354 - 16361
(2019/10/16)
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- Cephalosporin compounds
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Cephalosporin compounds represented by the general formula STR1 wherein R represents a group shown by formula STR2 wherein R1 represents a hydrogen atom or a lower alkyl group of 1-3 carbon atoms and R2 represents a hydrogen atom, a lower alkyl group of 1-3 carbon atoms, a phenyl group which may be substituted by an amino or hydroxy group, a cyano group, a carboxy group, or a carboxymethyl group; said R1 and R2 may form a cycloalkylidene group of 4-6 carbon atoms together with the carbon atom to which they are bonded) or a group shown by formula --CH2 --R3 (wherein R3 represents a hydrogen atom, a halogenomethyl group, a carbamoyl group, a carboxymethyl group, α4-carboxy-3-hydroxyisothiazol-5-yl-thiomethyl group, or α2-carboxyphenylthiomethyl group); R' represents a group shown by formula STR3 (wherein Ra represents a carboxy group, a cyano group, or a carbamoyl group which may be substituted by a lower alkyl group of 1-3 carbon atoms and Rb represents a hydrogen atom or an amino group) or a group shown by formula STR4 (wherein Ra and Rb have the same significance as above); and the waveline ? shows an anti-form or syn-form bond and the salts thereof. They possess excellent antibacterial activities against gram positive bacteria and gram negative bacteria, in particular, pseudomonas aeruginosa and are useful as anti-bacterial agents.
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