Anomeric effects of sulfones

The anomeric effect of the sulfone group in tetrahydropyrans has been determined. The value is >2 kcal mol –1 , which is larger than the A-value of a methyl group but less than the A-value of the sulfone in a tetrahydropyran. Hence, in an unsubstituted tetrahydropyranyl sulfone, the equatorial conformer predominates, whereas in a properly substituted methyltetrahydropyranyl sulfone, an axial sulfone is preferred over an axial methyl group.Key words: sulfone, tetrahydropyran, anomeric effect.