Examination Théorique de la Stéreoselectivité de la Réaction de Cycloaddition Intramoléculaire Diels-Alder de Triène-Amide [ Theoretical Examination of the Stereoselectivity of the Intramolecular Cycloaddition Diels-Alder Reaction of Triene-Amide ]

The stereoselectivity of the intramolecular cycloaddition Diels-Alder reaction (IMDA) of the triene amide molecule for the preparation of the hexahydroindoles products is made the object of this study. This reaction was carried out at a temperature of 160 degree Celsius and in the presence of the toluene solvent. The molecular mechanism of the observed of IMDA reaction were examined theoretically, by the DFT method at the B3LYP procedure and at the 6-31 G^sup **^ basis set level. The activation barrier based on the theory of the transition state to shown the preference of the Exo approach according to the mode α and β, this result is confirmed by the application of the maximum hardness principle. Otherwise, intrinsic reaction coordinate analysis and of the Wiberg index calculations applied to the transitions states have shown that, all reactions are asynchronous and concerted. These results are compatible with the experimental results.