E JALALI - Chemistry Department, Science Faculty, D amghan branch, Islamic Aza d University, Damghan, Iran
H YAHYAEI - Chemistry Department, Zanjan Branch, Islamic Azad University, Zanjan, Iran

The m ost dominant conforma tion-contro lling factor in carbohydrate compo unds is kno wn as the a nomeric eff ect (AE).۱-۳ If a pyranose ring ha s an electronegative substituent a t the anom eric carbon then this substituent is more likely to take the axial configuration tha n the equato rial configu ration. This is a conseq uence of a general effe ct (the gen eralized anomeric effect, GAE) that in a chain of atoms X-C -Y-C, in w hich Y and X are atoms with nonbonding electr on pairs (e.g. F, O, S, N), the synclinal conformation i s more likely. Although the importance of the hyperconjugative inter actions in so me acyclic compounds has investi gated, there is insufficient published experimental information about the stereoelctronic intera ctions in me thanedithio l. In this w ork, the i mpacts of the generalized anomeric effect (GAE) associated with electron delocalizations,۱-۳ steric and dipole-dipole int eractions o n the confo rmational an d structural properties of methaned ithiol were investigated computatio nally using hybrid-DFT and NBO i nterpretation .۴,۵

metha nedithiol , g eneralized anomeric effect , ab initio , NBO