Abstract: Dibornyl oxalates with different optical activity were synthesized by indirect esterification method from different chiral borneol with oxalyl chloride, and the target products could be easily purified to 99.9% (GC) through recrystallization with alcohol. The composition of the synthesized dibornyl oxalates were analyzed by chiral high-performance liquid chromatography (HPLC), and it was proved that there were (-)-dibornyl oxalate, mesomer and (+)-dibornyl oxalate in the synthesized racemic dibornyl oxalate, and the mass ratio was nearly 1:2:1. The location of hydrogen and carbon atoms in (-)-dibornyl oxalate was determined by means of ¹H-¹H COSY, HSQC and HMBC, and the spectra of different chiral dibornyl oxalate were contrasted including GC-MS, IR, ¹H NMR and ¹³C NMR. Furthermore, the synthetic racemic dibornyl oxalate was compared with the mixture of equal (+) and (-) dibornyl oxalates. The results showed that the spectral properties of (+), (-) and racemic dibornyl oxalate were similar, however these oxalates could be distinguished via optical activity. The mesomer, which contained in the synthesized racemic dibornyl oxalate from the reaction of racemic borneol and oxalyl chloride, owned different nuclear magnetic chemical environment and spectral properties of the carbon and hydrogen atoms on both sides. This reflected in the different chemical shifts of the hydrogen atoms on 8-and 8'-, 3-and 3'-, and the carbon atoms on 1-and 1'-, 3-and 3'-as well as 11-and 11'-positions.

Key words: optically active, borneol, oxalyl chloride, dibornyl oxalate, spectral properties