The reaction mechanism, thermodynamic and kinetic behavior of the dipole cycloaddition reaction of benzaldoxime with propinol have been studied by DFT method at B3LYP/6-31G* level. The results show that there are eight reaction channels, corresponding to eight transition states, in the reaction process. The main parts of all transition states are non-planar five-membered ring, in which the geometry of Z-benzaldoxime and E-benzaldoxime is maintained partially, but the bond length, bond angle and charge are all changed. The four reaction channels including hydroxyl-type benzaldoxime are endothermic reaction, thermodynamically non-spontaneous process, but the other four reaction channels including ion-type benzaldoxime participation are exothermic reaction and thermodynamically spontaneous process. The latter four reaction channels, which have lower reaction barriers, faster reaction velocities and bigger equilibrium constants than those of the former fours, are the chief reaction channels. Two kinds of products can be obtained in the addition reaction of benzaldoxime with propinol, in which 3-hydroxymethyl-dihydroisoxazol is the main product when reaction equilibrium is reached.

Key words: benzaldoxime, propinol, addition reaction, mechanism, theoretical research