Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions.

Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Research Abstract Details 

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Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Abstract Text:

Stephen Chamberland,Joseph W Ziller,K A Woerpel,

Nucleophilic substitution reactions of monosubstituted tetrahydropyran acetals give opposite selectivities when a remote alkyl or alkoxy substituent is present at C-4. Coupled with earlier computational reports on the intermediates of glycosylation reactions, these results are consistent with the preference for the oxocarbenium ion intermediate derived from alkoxy-substituted tetrahydropyran acetals to occupy a pseudoaxial conformation. Theoretical, spectroscopic, and X-ray crystallographic evidence of this conformational preference in an analogous and more stable dioxocarbenium ion are provided. This contrasteric preference for an axial orientation of an alkoxy substituent likely derives from the electronically favored pseudoaxial orientation of remote electronegative substituents in neutral six-membered rings possessing electron-deficient carbon atoms.

Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Publishing Authors By Initials

S Chamberland,JW Ziller,KA Woerpel,

For similar natural sciences: physics: thermodynamics research abstracts see: natural sciences: physics: thermodynamics research

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Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Journal Published:

PUBLICATION TYPE: Research Support, U.S. Gov't,

Journal: Journal of the American Chemical Society

VOLUME: 127

Page Numbers: 5322-3

Journal Abbreviation: J. Am. Chem. Soc.

ISSN: 0002-7863

DAY: 20

MONTH: Apr

YEAR: 2005

Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Information

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LANGUAGE: eng

NlmUniqueID: 7503056

Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Keywords Mesh Terms:

KEYWORDS: Thermodynamics

MESH TERMS: chemistry

Chemical & Substance for Abstract: Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions. Information

Substance Name: Pyrans

Registry Number: 0

Grant and Affiliation Information for Structural evidence that alkoxy substituents adopt electronically preferred pseudoaxial orientations in six-membered ring dioxocarbenium ions.

AFFILIATION: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.

Country: United States

AGENCY: United States NIGMS

GRANT: GM-61066

ACRONYM: GM

MEDLINETA: J Am Chem Soc

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