Thermodynamically controlled deracemization of some acyclic ketones bearing a chiral center at the position α to the carbonyl group was satisfactorily achieved. Acyclic ketones with high optical purities could be isolated after treatment of the racemic ketones with base in aqueous MeOH in the presence of (–)-(2R,3R)-trans-2,3-bis(hydroxydiphenylmethyl)-1,4-dioxaspiro[5.4]decane (1a). The efficiency
Stereochemical Control in Microbial Reduction. XXVIII. Asymmetric Reduction of<i>α</i>,<i>β</i>-Unsaturated Ketones with Bakers’ Yeast
作者:Yasushi Kawai、Kentarou Saitou、Kouichi Hida、Duc Hai Dao、Atsuyoshi Ohno
DOI:10.1246/bcsj.69.2633
日期:1996.9
Bakers’ yeastreduction of α,β-unsaturated ketones affords optically active saturated ketones contaminated by allylic and saturated alcohols as minor components. Stereoselectivity of the reduction of carbon–carbon double bond strongly depends on the structure of β-aryl substituent. The bakers’ yeastreduction of β-phenyl enones gives saturated ketones in moderate stereoselectivity. Stereoselectivity
CYCLIC PEPTIDE COMPOUND HAVING HIGH MEMBRANE PERMEABILITY, AND LIBRARY CONTAINING SAME
申请人:Chugai Seiyaku Kabushiki Kaisha
公开号:EP3636807A1
公开(公告)日:2020-04-15
The present inventors have found that when screening for cyclic peptide compounds that can specifically bind to a target molecule, the use of a library including cyclic peptide compounds having a long side chain in the cyclic portion can improve the hit rate for cyclic peptide compounds that can specifically bind to the target molecule. Meanwhile, the present inventors have found that tryptophan and tyrosine residues, which have conventionally been used in oral low molecular-weight pharmaceuticals and are amino acid residues having an indole skeleton or a hydroxyphenyl group, are not suitable for peptides intended to attain high membrane permeability.
Iridium phosphinitoxazoline complexes were found to be new efficient catalysts for the asymmetric hydrogenation of arylated alpha,beta-unsaturated ketones. Linear as well as cyclic substrates are hydrogenated with similar success, giving selectivities of up to 99.7% ee.