Solvent effects substituted tetrahydropyran

The magnitude of the anomeric effect depends on the nature of the substituent and decreases with increasing dielectric constant of the medium. The effect of the substituent can be seen by comparing the related 2-chloro- and 2-methoxy-substituted tetrahydropyrans in entries 2 and 3. The 2-chloro compound exhibits a significantly greater preference for the axial orientation than the 2-methoxy. Entry 3 also provides data regarding the effect of solvent polarity, where it is observed that the equilibrium constant is larger in carbon tetrachloride e = 2.2) than in acetonitrile (e = 37.5). 

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