Processes for the preparation of R-lipoic acid or S-lipoic acid comprising a process step selected from a) distillation of dihydrolipoic acid, b) reaction of  or its stereoisomer, where Ms is SO2—R′ and R and R′ independently of one another is [sic] C1-C6-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in ethanol and reaction with a complex hydride, (c) the extraction of a protic solution of R-dihydrolipoic acid or S-dihydrolipoic acid with organic solvents at a pH from 9 to 10, or (d) the extraction of R-dihydrolipoic acid or S-dihydrolipoic acid with organic solvents from a protic solution at a pH of 4 to 5, or a combination of one or more of steps (a) to (d), and processes for the preparation of dihydrolipoic acid and the compound 1,6,8 [lacuna] octanetriol.