Process for preparing optically active 3,3,3-trifluoromethyl-2-alkylpropionic acid derivatives

DETAILED DESCRIPTION What is claimed is: 1.
A process for preparing optically active 3,3,3-trifluoro-2-alkylpropionic acid derivatives of the general formulae ##STR4## in which R denotes ethyl or methyl and X denotes --OH or NH.
sub.
2, with the exception that, when R=methyl, X.
noteq.
OH, comprising the transformation of a racemic 3,3,3-trifluoro-2-alkylpropionamide of the general formula ##STR5## in which R and X have said meaning, either using microorganisms which are capable of utilizing the latter, as their sole source of nitrogen, in the form of the racemate or of one of its optically active isomers, or using a polypeptide which possesses amidohydrolase activity and which is capable of hydrolyzing the latter.
2.
The process as claimed in claim 1, wherein the racemic 3,3,3-trifluoro-2-alkylpropionamide of the general formula ##STR6## is prepared by hydrolyzing a 3,3,3-trifluoro-2-alkylpropiononitrile of the general formula ##STR7## with a mineral acid.
3.
The process as claimed in claim 2, characterized in that the mineral acid employed is sulfuric acid.
4.
The process as claimed in claim 2, characterized in that the hydrolysis is carried out at a temperature of from 20 to 140.
degree.
C.
5.
The process as claimed in claim 1, characterized in that the biotransformation is carried out using microorganisms of the genus Klebsiella.
6.
A process for preparing optically active 3,3,3-trifluoro-2-alkylpropionic acid derivatives of the general formula ##STR8## in which R denotes ethyl or methyl and X denotes --OH or NH.
sub.
2, with the exception that, when R=methyl, X.
noteq.
OH, characterized in that, in the first step, a racemic 3,3,3-trifluoro-2-alkylpropionamide of the general formula ##STR9## in which R and X have said meaning, is transformed, either using microorganisms which are capable of utilizing the latter, as their sole source of nitrogen, in the form of the racemate or of one of its optically active isomers, or using a polypeptide which possesses amidohydrolase activity and which is capable of hydrolyzing the latter, into an optically active 3,3,3-trifluoro-2-alkylpropionamide of the general formula ##STR10## in which R and X have said meaning, and the latter is then hydrolyzed, in the second step and in a known manner, into the optically active 3,3,3-trifluoro-2-alkylpropionic acid derivative (formula II)