نتایج جستجو برای: anomeric effect
تعداد نتایج: 1642348 فیلتر نتایج به سال:
Theoretical studies on the conformation of saccharides XII.* The anomeric effect in glycosyl halides
Molecular orbital calculations have been carried out on 2-fluorotetrahydropyran and 2-chlorotetrahydropyran as models for examining the anomeric effect in glycosyl halides. The calculated population of chair conformers depends on the solvent and for the axial form of fluoro derivative decreases from 90.6 % in dioxan to 37.0 % in water. For chloro derivative the dependence is less pronounced; th...
The generalized anomeric effect refers to the conformational preference of a gauche structure over an anti structure for molecules with a R-X-C-Y moiety. Whereas there are conflicting reports regarding the origin of this ubiquitous effect, a general consensus is that both the steric (more specifically electrostatic) and hyperconjugative interactions contribute. Here we employed the block-locali...
The block-localized wave function (BLW) method, which can derive optimal electron-localized state with intramolecular electron delocalization completely deactivated, has been combined with the polarizable continuum model (PCM) to probe the variation of the anomeric effect in solution. Currently both the hyperconjugation and electrostatic models have been called to interpret the anomeric effect ...
Oxazinane rings can undergo isomerization or transformation to 5-membered tuned by the anomeric effect.
Correction for ‘Stereoelectronic power of oxygen in control chemical reactivity: the anomeric effect is not alone’ by Igor V. Alabugin et al. , Chem. Soc. Rev. 2021, DOI: 10.1039/d1cs00386k.
Gas-phase electron-diffraction data and high-level quantum chemical calculations have been used to study the conformational behaviour of N-azidomethylpyrrolidine. The two most stable conformers with a relative abundance of about 80% at 298 K possess gauche orientation of the azidomethyl group around the C-N(pyr) bond (C-N(azido)gauche with respect to the endocyclic N(pyr)-C bond). This orientat...
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