182970-04-3Relevant articles and documents
Total Synthesis of the All-Rare Sugar-Containing Pentasaccharide Repeating Unit of the O-Polysaccharide of Plesiomonas shigelloides Strain 302-73 (Serotype O1)
Biswas, Sayantan,Ghotekar, Balasaheb K.,Kulkarni, Suvarn S.
, p. 6137 - 6142 (2021)
First total synthesis of the conjugation-ready pentasaccharide repeating unit of Plesiomonas shigelloides strain 302-73 (serotype O1) is reported. The complex target pentasaccharide is composed of all-rare amino sugars such as orthogonally functionalized d-bacillosamine, l-fucosamine, and l-pneumosamine linked through four consecutive α-linkages. The poor nucleophilicity of axial 4-OH of l-fucosamine and stereoselective glycosylations are the key challenges in the total synthesis, which was completed via a longest linear sequence of 27 steps in 3% overall yield.
1-PHENYLPYRROLE COMPOUNDS
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Page/Page column 33-34, (2010/04/28)
The present invention comprises a compound for the prevention and/or treatment of cardiovascular diseases, nephropathy, fibrosis, primary aldosteronism or edema. The compound is of the following general formula (I): wherein R1 represents a C1 -C3 alkyl group; R2 represents a hydroxy -C1 -C4 alkyl group and the like; R3 represents a halogeno group, a halogeno-C1 -C3 alkyl group and the like; R4 represents a hydrogen atom, a halogeno group and the like,- R5 represents a sulfamoyl group or a C1-C3 alkylsulf onyl group; R6 represents a hydrogen atom, a halogeno group and the like] or an N-oxide, atropisomer of the foregoing, or pharmaceutically acceptable salt of the foregoing.
Nitrile biotransformations for the synthesis of highly enantioenriched β-hydroxy and β-amino acid and amide derivatives: A general and simple but powerful and efficient benzyl protection strategy to increase enantioselectivity of the amidase
Ma, Da-You,Wang, De-Xian,Pan, Jie,Huang, Zhi-Tang,Wang, Mei-Xiang
, p. 4087 - 4091 (2008/09/20)
(Chemical Equation Presented) Biotransformations of a number of racemic β-hydroxy and β-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the substrates. While biotransformations of β-hydroxy and β-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the β-hydroxy and β-amino of nitrile substrates led to the formation of highly enantioenriched β-benzyloxy and β-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure β-hydroxy and β-amino acids.
Dramatic enhancement of enantioselectivity of biotransformations of β-hydroxy nitriles using a simple O-benzyl protection/docking group
Ma, Da-You,Zheng, Qi-Yu,Wang, De-Xian,Wang, Mei-Xiang
, p. 3231 - 3234 (2007/10/03)
Catalyzed by the Rhodococcus erythropolis AJ270 whole cell catalyst, the O-benzylated β-hydroxy alkanenitriles underwent remarkably high enantioselective biotransformations, whereas the biotransformations of free β-hydroxy alkanenitriles gave very low ena
Enantiomerically-enhanced nutritional energy substrates
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, (2008/06/13)
Synthetic enantiomeric esters are employed as energy substrates for parenteral or enteral nutritional formulations. The substrates are provided in substantially monoisomeric or anomeric forms readily utilized in patient metabolism.
Synthesis and structure of linear and cyclic oligomers of 3- hydroxybutanoic acid with specific sequences of (R)- and (S)-configurations
Bachmann, Beat M.,Seebach, Dieter
, p. 2430 - 2461 (2007/10/03)
To study the stereoselectivity of enzymatic cleavage of poly(3- hydroxybutyrates) (PHB) in a well-defined system (purified depolymerase and monodisperse substrate of specific relative configuration), linear and cyclic oligomers of HB (OHBs) containing (R)- and (S)-3-hydroxybutanoate residues were synthesized. The starting material (R)-HB was prepared from natural sPHB, and (S)-HB by enantioselective reduction of 3- oxobutanoate with yeast or with H2/Noyori-Taber catalyst (Scheme2). The HB building blocks were then prolected (O-benzyl/tert-butyl ester; Scheme 3) and coupled to give dimers 3, 4, tetramers 5-9, and octamers 10-18; for analytical comparison, a 3mer, 5mer, 6mer, and 7mer (19-22) were also prepared. Two of the tetramers were subjected to macrolactonization conditions (Yamaguchi) to give the cyclic tetramers 23 and 25 and octamers 24 and 26. All new compounds were fully characterized (m.p., [α](D), CD, IR, 1H- and 13C-NMR, MS, elemental analysis). Single-crystal X-ray structure analyses were performed with oligolides 24 and 25 (Figs. 2 and 4), and the structures, as well as the crystal packing, were compared with those of analogs containing only (R)-HB units or consisting of 3-amino- instead of 3-hydroxybutanoic-acid moieties.
