The conformational preference and barrier to internal rotation of an equatorial 3,5-dichlorophenyl group by the J method. Derivatives of cyclohexane, 1,3-dithiane, 1,3-dioxane, and 1,3-dioxolane

Abstract

(1979) We report the preparation and the analysis of the phenyl ring proton magnetic resonance spectra of 3,5-dichlorophenylcyclohexane and of the 2-(3,5-dichlorophenyl) derivatives of 1,3-dioxane, 1,3-dithiane, and 1,3-dioxolane. With the exception of the dioxolanes these compounds exist predominantly as the equatorial isomers. The J method is used to show that the phenyl moiety prefers the conformation in which the x C-H bond lies in the phenyl La faible valeur pour la barriere, dans le derive dioxanne-1,3, est en bon accord avec des calcuis de mtcanique molCculaire et avec les resultats d'etudes calorimetriques et de diffraction de rayons-X sur le phenyl-2 dioxanne-1,3 equatorial.[Traduit par le journal]

Chiroptical Properties of the Benzene Chromophore. A Method for the Determination of the Absolute Configurations of Benzene Compounds by Application of the Benzene Sector and Benzene Chirality Rules

“…For benzene compounds with a contiguous chiral center incorporating a hydrogen atom, empirical potential function 65 and molecular orbital calculations − as well as X-ray, , proton nuclear magnetic resonance, ,− gas electron diffraction, and jet laser spectroscopy indicate that the preferred conformation ( 5 ) is such that the hydrogen atom at the carbon center eclipses or almost eclipses the phenyl ring plane (Table ). Thus the CD data in Table suggest the quadrant projections in Figure A which show the sign of the vibronic contribution to the 1 L b CEs of a monosubstituted benzene chromophore by atoms or groups attached to a chiral center and lying in sectors in front of the benzene ring plane (near sectors).…”