METHOD FOR PRODUCING LIPOIC ACID AND DIHYDROLIPOIC ACID

摘要

The invention relates to a method for producing R-lipoic acid and S-lipoic acid comprising a step selected from the following: (a) distillation of dihydrolipoic acid, (b) reaction of (2) or the stereoisomer thereof, wherein Ms represents SO2-R', and R and R' independently mean C1-C6-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulphide and sulphur in ethanol and reaction with a complex hydride, (c) extraction of a protic solution of R dihydrolipoic acid or S-dihydrolipoic acid with an organic solvent at a pH value of 9 -10, or (d) extraction of R-dihydrolipoic acid or S-dihydrolipoic acid with an organic solvent from a protic solution at a pH value of 4 - 5, or a combination of individual or several steps (a) - (d). The invention also relates to a method for producing dihydrolipoic acid and the compound 1,6,8 octane triol.