Reaction of caesium 4-chlorophenate and chlorohydrins from threonines: synthesis of clofibrate analogues
摘要:
Clofibrate is a well-known peroxisome prolifierator-activated receptor-alpha (PPARalpha) agonist, used in the treatment of hyperlipaemias and atherosclerosis and to prevent heart failure. Herein, the preparation of the four enantiomerically pure stereoisomers of ethyl 2-(4-chlorophenoxy)-3-hydroxybutanoate as clofibrate analogues is described. Biological evaluation of these new compounds was performed by a transactivation assay in a transiently transfected monkey kidney fibroblast cell line. All four diastereomers were inactive even at 300 muM, where clofibrate showed an evident activity, suggesting that the designed clofibrate molecular structural modifications in the analogues caused the loss of peroxisome proliferator-activated receptor-alpha (PPARalpha) activity. (C) 2005 Elsevier Ltd. All rights reserved.
Reaction of caesium 4-chlorophenate and chlorohydrins from threonines: synthesis of clofibrate analogues
摘要:
Clofibrate is a well-known peroxisome prolifierator-activated receptor-alpha (PPARalpha) agonist, used in the treatment of hyperlipaemias and atherosclerosis and to prevent heart failure. Herein, the preparation of the four enantiomerically pure stereoisomers of ethyl 2-(4-chlorophenoxy)-3-hydroxybutanoate as clofibrate analogues is described. Biological evaluation of these new compounds was performed by a transactivation assay in a transiently transfected monkey kidney fibroblast cell line. All four diastereomers were inactive even at 300 muM, where clofibrate showed an evident activity, suggesting that the designed clofibrate molecular structural modifications in the analogues caused the loss of peroxisome proliferator-activated receptor-alpha (PPARalpha) activity. (C) 2005 Elsevier Ltd. All rights reserved.
A recombinant ketoreductase tool-box. Assessing the substrate selectivity and stereoselectivity toward the reduction of β-ketoesters
作者:Dunming Zhu、Chandrani Mukherjee、J. David Rozzell、Spiros Kambourakis、Ling Hua
DOI:10.1016/j.tet.2005.10.044
日期:2006.1
The substrate selectivity and stereoselectivity of a series of ketoreductases were evaluated toward the reduction of two sets of beta-ketoesters. Both the structural variety at beta-position and the substituent at alpha-position greatly affected the activity and stereoselectivity of these ketoreductases. For the first set of beta-ketoesters, at least one ketoreductase was found that catalyzed the formation of either (D) or (L) enantiomer of beta-hydroxyesters from each substrate with high optical purity, with the only exception of ethyl (D)-3-hydroxy3-phenylpropionate. For the second set of beta-ketoesters with alpha-substituents, the situation is more complex. More commonly, a ketoreductase was found that formed one of the four diastereomers in optically pure form, with only a few cases in which enzymes could be found that formed two or more of the diastereomers in high optical purity. The continued development of new, more diverse ketoreductases will create the capability to produce a wider range of single diastereomers of 2-substituted-3-hydroxy acids and their derivatives. (c) 2005 Elsevier Ltd. All rights reserved.
A new enantioselective synthesis of glycidates via dynamic kinetic resolution of racemic 2-chloro-3-keto esters using chiral Ru (II) complexes
作者:Jean-Pierre Genêt、M.C. Caño de Andrade、V. Ratovelomanana-Vidal
DOI:10.1016/0040-4039(95)00182-c
日期:1995.3
2-chloro-3-keto esters were quantitatively hydrogenated to syn and anti 2-chloro-3-hydroxyester by asymmetric hydrogenation with chiral ruthenium (Ii) catalysts prepared in-situ from (COD)Ru(2-Methylallyl)(2) in presence of atropisomeric ligands such as MeO-Biphep and Binap, giving enantioselectivity up to 99%. 2-chloro-3-hydroxy esters were treated with different bases to give (E)- and (Z)-2,3-epoxyalkanoates in 65-90% yields with 84-97% ee.
Several aliphatic or aromatic 2-chloro-3-oxoesters are stereoselectively reduced by yeast or fungal strains, affording in fair to good yield and high enantiomeric excess some of the respective 2-chloro-3-hydroxyester stereoisomers.
Reaction of caesium 4-chlorophenate and chlorohydrins from threonines: synthesis of clofibrate analogues
作者:Maria Grazia Perrone、Ernesto Santandrea、Leonardo Di Nunno、Antonio Scilimati、Vincenzo Tortorella、Francesco Capitelli、Valerio Bertolasi
DOI:10.1016/j.tetasy.2005.01.006
日期:2005.2
Clofibrate is a well-known peroxisome prolifierator-activated receptor-alpha (PPARalpha) agonist, used in the treatment of hyperlipaemias and atherosclerosis and to prevent heart failure. Herein, the preparation of the four enantiomerically pure stereoisomers of ethyl 2-(4-chlorophenoxy)-3-hydroxybutanoate as clofibrate analogues is described. Biological evaluation of these new compounds was performed by a transactivation assay in a transiently transfected monkey kidney fibroblast cell line. All four diastereomers were inactive even at 300 muM, where clofibrate showed an evident activity, suggesting that the designed clofibrate molecular structural modifications in the analogues caused the loss of peroxisome proliferator-activated receptor-alpha (PPARalpha) activity. (C) 2005 Elsevier Ltd. All rights reserved.