dimethyl (3S)-3-hydroxyoctanedioate

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 45.3 g (0.2 mol) of enantiomerically pure dimethyl (3S)-3-hydroxyoctanedioate were mixed in a Haake kneader at from 30 to 40° C. with 5.2 g of sodium borohydride (0.14 mol, 0.7 equivalents). The reaction mixture was kneaded until the reaction was complete (TLC monitoring, 40 min). The intermediate methyl borate was then taken up in methanol and hydrolyzed under acidic conditions. The desired methyl (6S)-6,8-dihydroxyoctanoate was extracted with ethyl acetate. After drying the organic phase, this was cooled to 0° C., and the product which crystallized out was filtered off. 34.5 g of methyl (6S)-6,8-dihydroxyoctanoate in the form of white crystals were obtained (90% yield). (TLC monitoring, 40 min) The desired methyl (6S)-6,8-dihydroxyoctanoate was extracted with ethyl acetate After drying the organic phase the product which crystallized out was filtered off