Dynamic 1H-NMR demonstration of anomeric effect and structure: conformational and configurational analysis of N-2-(1,4-dioxane)-N`-(p-methylbenzenesulfonyl)- O-(p-methylphenoxy) İsourea

Authors : Ali Reza MODARRESI-ALAM, Hossein A. DABBAGH

Pages : 607-619

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The conformational and configurational behavior and the structure of N-2-insert ignore into journalissuearticles values(1,4-dioxane);-N`-insert ignore into journalissuearticles values(p-methylbenzenesulfonyl);-O- insert ignore into journalissuearticles values(p-methylphenoxy); isourea insert ignore into journalissuearticles values(1); were studied using dynamic NMR. The endo-anomeric effect, hydrogen bonding, temperature, and polarity of solvent control the population of dioxane ring conformers or anomers but not the configuration interconversion of the imine of the imidoyl moiety. Dynamic 1H-NMR, D H°, D S°, D G°, and D G\ddag analysis of 1 demonstrates that the dioxane ring adopts the chair conformation, that the imidoyl amino group prefers axial conformation, and that the tosyl and tolyl groups about the C=N bond retain the E configuration.
Keywords : Anomeric effect, dynamic NMR, conformational analysis, configurational analysis, hydrogen bonds, dioxane, aminoimidoyl