Abstract: The invention relates to a process for the production of (R)- or (S)-8-chloro-6-hydroxyoctanoic acid alkyl esters of the general formula (R)-II or (S)-II, in which R means C1-4 alkyl, from 8-chloro-6-oxo-octanoic acid alkyl esters of the general formula I, in which R has the above meaning. The desired enantiomers are produced biocatalytically in an enantioselective reduction, wherein as desired the strains Mucor racemosus are used for (S)-II compounds and Geotrichum candidum for (R)-II compounds. The resultant esters may, in known manner, be converted stereospecifically into (R)-?-lipoic acid.

Abstract: The invention relates to a process for the production of (R)- or (S)-8-chloro-6-hydroxyoctanoic acid alkyl esters of the general formula (R)-II or (S)-II, in which R means C1-4 alkyl, from 8-chloro-6-oxo-octanoic acid alkyl esters of the general formula I, in which R has the above meaning. The desired enantiomers are produced biocatalytically in an enantioselective reduction, wherein as desired the strains Mucor racemosus are used for (S)-II compounds and Geotrichum candidum for (R)-II compounds. The resultant esters may, in known manner, be converted stereospecifically into (R)-?-lipoic acid.

Abstract: The invention relates to a process for the preparation of compounds of the general formula I in which R1 represents a C1-C20-alkyl group, a C3-C12-cycloalkyl group, a C7-C12-aralkyl group or a mono- or bi-nuclear aryl group, in which a ketone of formula II wherein R1 is as defined above, is subjected to asymmetric hydrogenation.

Abstract: The invention relates to a process for the preparation of compounds of the general formula I 1

Abstract: The invention relates to a process for the production of (R)- or (S)-8-chloro-6-hydroxyoctanoic acid alkyl esters of the general formula (R)-II or (S)-II, 1

Abstract: The invention relates to a process for the preparation of compounds of the general formula I in which R1 and R2 are identical or different and are a C1-C20-alkyl group, C3-C12-cycloalkyl group, C7-C12-aralkyl group or a mono- or binuclear aryl group, in which a ketone of the formula III or IV in which R1 and R2 have the above meaning, is asymmetrically hydrogenated.

Abstract: The invention relates to a process for the preparation of compounds of the general formula I ##STR1## in which R.sup.1 and R.sup.2 are identical or different and are a C.sub.1 -C.sub.20 -alkyl group, C.sub.3 -C.sub.12 -cycloalkyl group, C.sub.7 -C.sub.12 -aralkyl group or a mono- or binuclear aryl group, in which a ketone of the formula III or IV ##STR2## in which R.sup.1 and R.sup.2 have the above meaning, is asymmetrically hydrogenated.

Abstract: The invention relates to the production and purification of salts of 6,8-bis (amidiniumthio)octanoic acid, its enantiomers (+)-6,8-bis(amidiniumthio)octanoic acid and (-)-6,8-bis (amidiniumthio)octanoic acid and of the esters of these compounds as well as to their use to produce dihydrolipoic acid and .alpha.-lipoic acid.

Abstract: The invention relates to (+) and (-)-8-halogen-6-hydroxy-octanoic acid enantiomers wherein the halogen is Cl, Br, or I, and their respective preparatory processes.

Abstract: The invention relates to (+) and (-)-8-halogen-6-hydroxy-octanoic acid enantiomers wherein the halogen is Cl, Br, or I, and their respective preparatory processes.

Abstract: The invention relates to the production and purification of salts of 6,8-bis(amidiniumthio) octanoic acid, its enantiomers (+)-6,8-bis(amidiniumthio)octanoic acid and (-)-6,8-bis (amidiniumthio)octanoic acid and of the esters of these compounds as well as to their use to produce dihydrolipoic acid and .alpha.-lipoic acid.

Abstract: The synthesis of pure enantiomers of 8-chloro-6-sulfonyloxy-octanoic acids and their alkyl esters and of pure enantiomers of 6,8-dichloro-octanoic acid and its alkyl esters as intermediates for the synthesis of the enantiomers of .alpha.-liponic acid as well as a method for converting the two enantiomers of 8-chloro-6-hydroxy-octanoic acid into an enantiomer of .alpha.-liponic acid.