Lipase-catalyzed resolution of esters of 4-chloro-3-hydroxybutanoic acid: effects of the alkoxy group and solvent on the enantiomeric ratio
摘要:
Various lipases have been investigated for their potential use as catalysts for the resolution of esters of 4-chloro-3-hydroxybutanoic acid via transesterification in organic solvents. Rhizomucor miehei lipase was found to be the most efficient lipase, with the enantiomeric ratio (E) being dependent upon of the nature of the alkoxy group of the ester and the resolution medium. Higher E-values were obtained when transesterification was performed in benzene or carbon tetrachloride than was the case in hexane. In mixtures of benzene and hexane the trend in E-values followed a linear relationship. (C) 1999 Elsevier Science Ltd. All rights reserved.
[DE] VERFAHREN ZUR HERSTELLUNG VON 4-CYANO-3-HYDROXYBUTTERSÄUREESTERN<br/>[EN] METHOD FOR PRODUCING 4-CYANO-3-HYDROXYBUTYRIC ACID ESTERS<br/>[FR] PROCEDE POUR PRODUIRE DES ESTERS DE L'ACIDE 4-CYANO-3-HYDROXYBUTYRIQUE
申请人:BAYER CHEMICALS AG
公开号:WO2005005375A1
公开(公告)日:2005-01-20
Bereitgestellt wird ein Verfahren zur Herstellung von 4-Cyano- 3-hydroxybuttersäureestem durch Umsetzung eines 4-substituierten 3-Hydroxybuttersäureesters mit einern Cyanidsalz in einern organischen Lösungsmittel in Gegenwart eines oder mehrerer weiterer Salze.
Process for the preparation of (s)-or (r)-4-halo-3-hydroxybutyrates
申请人:Mettler Hanspeter
公开号:US20070078279A1
公开(公告)日:2007-04-05
Process for the preparation of enantiomerically pure (S)- or (R)-4-halo-3-hydroxybutyrates of formula (I), wherein R
1
is CH
2
X, CHX
2
or CX
3
and X independently represents Cl and/or Br and wherein R
2
is C
1-6
-alkyl, C
3-8
-cycloalkyl, aryl or aralkyl, each aryl or aralkyl being optionally further substituted with one or more C
1-4
-alkyl groups and/or halogen atoms, by asymmetric hydrogenation of 4-halo-3-oxobutyric acid esters of formula (II), wherein R
1
, R
2
and X are as defined above in the presence of a catalyst of a ruthenium complex comprising a chiral ligand of the formula (III).
The present invention provides a process for producing optically active compounds by a biochemical method in which specific compounds having hydroxyl groups are reacted with esters in the presence of hydrolases. The compounds have the following general formula:
wherein X is selected from halogen atoms and a cyano group. Y is selected from the group constituting substituted phenyl groups, halogen atoms, cyano, trifluoromethyl and amino groups and alkylamino and alkyloxycarbonyl groups in which alkyl groups have 1-20 carbon atoms. R is an alkylene group having 1-20 carbon atoms and n is 0 or 1.
This invention has its objects to provide a process for producing a butyric acid ester derivative of the above general formula (2) which is capable of removing various impurity byproducts whose formation cannot be avoided by the prior art technology, particularly the compound of the above general formula (1), with good efficiency.
This invention is related to a process for producing a butyric acid ester derivative of the general formula (2) which comprises treating a mixture containing a compound of the following general formula (1) with an addition reagent capable of adding itself to said ethylenic bond to thereby convert said compound of the general formula (1) to an addition product which can be easily separated from said butyric acid ester derivative of the general formula (2) and a process for producing a butyric acid ester derivative of the general formula (2) which comprises reacting a compound of the general formula (3) with a salt of prussic acid by a flow method.
HOCH2-CH=CH-COOR (1)