Hyperconjugative origin, of the anomeric

Fuchs et al. (129). They suggested that when the molecular dipoles of the axial and equatorial conformers are of similar magnitude, the more polar double bond-no bond structure, resulting from hyperconjugative interactions in the axial conformer, 54a (see Scheme 20), will be stabilized in the more polar solvent. This hypothesis would support the importance of the hyperconjugative origin of the anomeric effect. The appearance of a large proportion of the axial conformers of 2-(arylseleno)-l,3-dithianes 37 (Scheme 13), even in... 

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