Theoretical Study on the Geometry and Properties of Chiral Dihydrofuran Derivant C₂₁H₂₁NO₃

Molecular dynadrics imitation leer approach has been first used to optimize the geometry of cyclopropane spiro-compound (C₂₁H₂₁NO₃) in the lowest energy, and then semiempirical quantum chemical method AM 1 and PM3 were used to optimize its geometry the optimized geometry parameters consisted with the results of X-ray crystal determination. Its vibrational analysis was also done and the characteristic absorption peaks of its infrared spectrum were attributed to Certain bonds in the compound. Furthermore used the same methods were used to predict the geometry parameters of chiral dihydrofuran derivant C₂₁H₂₁NO₃, which is the by-product in synthesizing chiral cyclopropane spiro-compound. With the optimized parameters, its vibrational analysis was done. The calculable infrared spectrum is consistent with its experimental infrared spoectrum.