Question

Which one is more stable: anti conformation or gauche of Newman projection for ethane-1,2-diol? Why?

Answer 1

Given the real possibility of intramolecular hydrogen bonding we don't know.

Explanation:

Ordinarily, we would predict that the anti conformation would be the most stable. Certainly it would be for the `C_2-C_3` conformers of `"n-butane"`.

For `HOCH_2CH_2OH` there is certainly the possibility of intramolecular hydrogen bonding, in which the electropositive hydroxyl hydrogen is electrostatically attracted to the electronegative oxygen on the alternate hydroxyl group. Make a model, and make a few predictions.......