FIELD: chemical industry. SUBSTANCE: described are new (+) or (-)-8-halogen-6-hydroxyoctane acids of formula I: 
wherein X is Cl, Br, I, alkyl esters thereof of formula II: 
and salts thereof with alpha-methyl benzyl amine of formula III: 
. Method of preparing isomers of 8-halogen-6-hydroxyoctane acid of formula I by decomposition of pure diastereometric acids of formula III by treatment with inorganic or organic acids or bases. Described is method of preparing 8-halogen-6- hydroxyoctane acid alkyl esters of formula II by converting 8-halogen-6-hydroxyoctane acid of formula I into compound of formula II in the presence of catalytic amounts of HCl of temperatures from 50 to 100 C, preferably at 60 C. Solvent is corresponding alcohol and reaction is carried out stereospecifically, and configuration is retained, described is method of preparing salts of formula III by treating racemic mixture of (+)-8-halogen-6-hydroxyoctane acid and (-)-8- halogen-6-hydroxyoctane acid or any other mixture of isomers(+) and (-) of 8-halogen-6-hydroxyoctane acid with enantiomers of alpha- methylenzyl amine in solution and diastereometric compounds are then recrystallized. EFFECT: new intermediate products for preparation of alpha-lipoic and dihydrolipoic acids. 11 cl, 19 ex
