Abstract: Using density functional theory B3LYP, the author investigated the chiral transition process of the asparagine molecule under the complex condition of double water at the level of 6-311+G(2-df). The author drawed a complete asparagine molecule chiral transition path reaction potential energy surface by finding structures of the extreme value points including the transition states and intermediates, and analyzed the geometric and electronic structure properties of extreme value points. The results show that the hydrogen atom on the chiral carbon atom of Sasparagine molecule can transfer to the other side of the carbon atom via the oxygen atoms of carboxyl atoms as abridge, and achieve the chiral transition of asparagine molecule from Stype to Rtype. On this path there are four intermediates and five transition states. The maximum reaction energy barrier is 317.948 1 kJ/mol, which comes from the fourth transition state TS₂-R-Asn&2H₂O₁.

Key words: transition state, asparagine, chirality, reaction energy barrier