IJIAS-14-217-03.pdf - International Journal of Innovation...

International Journal of Innovation and Applied Studies
ISSN 2028-9324 Vol. 8 No. 2 Sep. 2014, pp. 720-727
© 2014 Innovative Space of Scientific Research Journals
Corresponding Author: Tourya Bedda 720
ETUDE THEORIQUE PAR LA METHODE D.F.T. DE LA REGIO ET STEREO-SELECTIVITE DE LA
CONDENSATION DU β-HIMACHALENE AVEC L’ACIDE m-CHLOROPERBENZOIQUE
(m-CPBA) DANS LE DICHLOROMÉTHANE
[ THEORETICAL STUDY BY D.F.T. OF REGION AND STEREO-SELECTIVITY OF
CONDENSATION OF β-HIMACHALENE WITH m-CHLOROPERBENZOIC ACID (m-CPBA)
IN DICHLOROMETHANE ]
Tourya Bedda
1
, Ahmed Benharref
2
, and Habib Elalaoui Elabdellaoui
1
1
Laboratoire de Chimie Physique, Département de Chimie,
Faculté des Sciences Université Chouaib Doukkali, BP 20, 24000 EL Jadida, Maroc
2
Laboratoire de Chimie des Substances Naturelles,
Faculté des Sciences Semlalia, Univesité Cadi Ayyad, BP. 2390 Marrakech, Maroc
Copyright © 2014 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License ,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
A
BSTRACT
:
The study of the β-himachalène attack by m-chloroperbenzoic acid (m-CPBA) in dichloromethane at room
temperature by the method ab initio quantum DFT/B3LYP 21G-3 contributes to the calculation of the reaction enthalpy,
entropy reaction, free enthalpy of reaction and activation energies. From the results, we could infer that this reaction leads
to a single product P1 regiospecifically the β-époxyhimachalène quantitative yield.
A geometric study of β-himachalène showed that the number of conformers is relatively low due to the C6 = C7 double bond
that involves a carbon atom of the junction between the two cycles.
The values of the enthalpies of reaction, the reaction of free enthalpies and entropies of the reaction on the action of β-
dibromocarbene himachalène at room temperature showed that the condensation of the β-dibromocarbene himachaléne is
at the C6 = C7 double bond in α position and the attack by the β face is impossible, these values have allowed us to conclude
that the reaction is exothermic.
The values of HOMO and LUMO energies showed that the reaction takes place by charge transfer with Normal electronic
demand NED.
K
EYWORDS
:
the reaction enthalpies, entropies reaction, free enthalpy of reaction, activation energies, stereoselective,
regional selectivity, HOMO, LUMO.
R
ÉSUMÉ
:
L’étude de l’attaque du β- himachalène par l’acide m-chloroperbenzoique (m-CPBA) dans le dichlorométhane à
température ambiante par la méthode quantique ab initio DFT/B3LYP 3-21G contribue au calcul des enthalpies de réaction,
entropies de réaction, enthalpies libres de réaction et des énergies d’activation. A partir des résultats obtenus, nous avons pu
déduire que cette réaction conduit à un seul produit P
1
régiospécifiquement au β-époxyhimachalène avec un rendement
quantitatif.