| Abstract: | R-(+)-6,8-dichlorooctanic acid was obtained in chiral resolution of 6,8-dichlorooctanic acid by using chiral split agent S-(-)-α-phenylethylamine. R-(+)-α-lipoic acid was synthesized by sulfuration and hydrolysis from R-(+)-6,8-dichlorooctanic acid ethyl ester that was prepared through esterfication reaction. The conditions were investigated and the results showed that the yield and specific rotation were influenced by feed ratio，solvent，catalyst and reaction temperature. Proper experimental condition for chiral reaction was found as：nS-(-)-α-phenylethylamine]∶n（6,8-dichlorooctanic acid）=0.45∶1，solvent was ethyl acetate. The optimal esterfication reaction conditions was found as：the catalyst was p-toluene sulfonic acid，reaction time 7 h. The optimum conditions of sulfuration reaction were found as：reaction temperature was 65 ℃，the amount of phase transfer catalyst was 0.4 g; The overall yield was 48.4%. The product and intermediate were characterized by IR，specific rotation and 1H NMR. |
