Abstract：Resolution of chiral acids by lipase is a hot and difficult topic. As acyl receptors in chiral resolution, aliphatic alcohols have great influence on their selectivity. The aim of this study is to investigate the effect of aliphatic alcohols with different carbon chain lengths as acyl receptors on the resolution of mandelic acid enantiomers. Different aliphatic alcohols were selected and esterified with mandelic acid in isopropyl ether. The results showed that with the increase of chain length of aliphatic alcohols, the selectivity decreased and the conversion increased. The selectivity of medium-chain aliphatic alcohols with 5-8 carbon atoms was not significantly different from that of short-chain aliphatic alcohols with 1-4 carbon atoms, but the conversion increased greatly, while the selectivity of long-chain aliphatic alcohols with more than 8 carbon atoms was poor. Among the middle-chain aliphatic alcohols, n-amyl alcohol was superior to the others. The effects of various conditions on the reaction of mandelic acid and n-amyl alcohol were investigated, and the optimal condition was obtained as follows: reaction time 5 h, temperature 30 ℃, shaking speed 200 r/min, enzyme dosage 200 mg, and the molar ratio of mandelic acid to amyl alcohol 1:4. In this condition, enantiomeric excess of amyl mandelate was 70.09% and conversion was 23.40%.
