140632-55-9Relevant academic research and scientific papers
Structure and absolute configuration of new acidic metabolites from Stachys ehrenbergii
Cincinelli, Raffaella,Scaglioni, Leonardo,Arnold, Nelly A.,Dallavalle, Sabrina
supporting information; experimental part, p. 5972 - 5975 (2011/11/30)
Two novel metabolites have been isolated from the aerial parts of Stachys ehrenberiigii. Their structures and stereochemistry were elucidated using a combination of 13C and 1H homo and heteronuclear 2D NMR experiments and mass analysis. The development of an enantioselective synthesis of 3-(2′-acetoxy-4-phenylbut-3′-enoylamino)propionic acid allowed to confirm the structure and assign the (R) absolute configuration at C-2′ of the natural product.
Direct asymmetric hydrogenation of 2-oxo-4-arylbut-3-enoic acids
Zhu, Lvfeng,Meng, Qinghua,Fan, Weizheng,Xie, Xiaomin,Zhang, Zhaoguo
supporting information; experimental part, p. 6027 - 6030 (2010/11/18)
A challenging direct asymmetric hydrogenation of (E)-2-oxo-4-arylbut-3- enoic acids to give 2-hydroxy-4-arylbutanoic acids (85.4-91.8% ee) was achieved with a Ru catalyst based on SunPhos as the chiral ligand. Further investigation of the reaction revealed that partial isomerization of 2-hydroxy-4-arylbutenoic acids was involved in the hydrogenation process. Employing the reaction conditions to the hydrogenation of 2-oxo-4-phenylbutanoic acid resulted in better enantioselectivity (91.8% ee) and efficiency (TON = 2000, TOF = 200 h-1), which offers a useful method for the synthesis of a common intermediate for ACE inhibitors.
The substrate spectrum of mandelate racemase: Minimum structural requirements for substrates and substrate model
Felfer, Ulfried,Goriup, Marian,Koegl, Marion F.,Wagner, Ulrike,Larissegger-Schnell, Barbara,Faber, Kurt,Kroutil, Wolfgang
, p. 951 - 961 (2007/10/03)
Mandelate racemase (EC 5.1.2.2) is one of the few biochemically well-characterized racemases. The remarkable stability of this cofactor-independent enzyme and its broad substrate tolerance make it an ideal candidate for the racemization of non-natural α-hydroxycarboxylic acids under physiological reaction conditions to be applied in deracemization protocols in connection with a kinetic resolution step. This review summarizes all aspects of mandelate racemase relevant for the application of this enzyme in preparative-scale biotransformations with special emphasis on its substrate tolerance. Collection and evaluation of substrate structure-activity data led to a set of general guidelines, which were used as basis for the construction of a general substrate model, which allows a quick estimation of the expected activity for a given substrate.
Chemo-enzymatic synthesis of (R)-and (S)-2-hydroxy-4-phenylbutanoic acid via enantio-complementary deracemization of (±)-2-hydroxy-4-phenyl-3- butenoic acid using a racemase-lipase two-enzyme system
Larissegger-Schnell, Barbara,Kroutil, Wolfgang,Faber, Kurt
, p. 1936 - 1938 (2007/10/03)
Deracemization of (±)-2-hydroxy-4-phenylbut-3-enoic acid was accomplished by lipase-catalyzed kinetic resolution coupled to mandelate racemase-mediated racemization of the non-reacting substrate enantiomer. Stepwise cyclic repetition of this sequence led
Enzymatic resolution of 2-hydroxy-4-phenylbutanoic acid and 2-hydroxy-4-phenylbutenoic acid
Chadha,Manohar
, p. 651 - 652 (2007/10/02)
Racemic 2-hydroxy-4-phenylbutanoic acid and 2-hydroxy-4-phenyl-butenoic acid have been resolved using a lipase. In each case, the (R)-2-hydroxy and the (S)-2-acetoxy acids were isolated with high enantiomeric excess and yield.
Polyfunctional (R)-2-Hydroxycarboxylic Acids by Reduction of 2-Oxo Acids with Hydrogen Gas or Formate and Resting Cells of Proteus vulgaris
Schummer, Anita,Yu, Hongtao,Simon, Helmut
, p. 9019 - 9034 (2007/10/02)
Various (R)-2-hydroxy acids such as (R)-2-hydroxy-3-enoic-, 3,5-dienoic-, 4-oxo-, (R,S)-3-hydroxy and some others were prepared on a scale up to 0.12 mol by biocatalytic reduction of the corresponding 2-oxo acids with P. vulgaris and hydrogen gas and/or formate as electron donors.With the exception of the 2-hydroxy-4-oxo acids it could be proved that the enantiomeric excess is >97 percent.For the 4-oxo derivatives this enantiomeric excess can be assumed.The yields of isolated products are high because they were isolated from rather small amounts of biocatalyst and low buffer concentrations.Product concentrations in the range of 0.1- 0.24 M were obtained.For 1 mmol of product formation in 15-20 h about 20-40 mg (dry weight) of P. vulgaris cells are necessary.
