Glycol is unusual in that the gauche conformation is more stable than the anti conformation. Why? Thanks!?

Answer 1

I suspect it has to do with hydrogen bonding of the adjacent alcohol groups, but don't take this as "gospel" it should be described in you chemistry book.

Added:

I found a reference to it; ethanes with small electronegative atoms, substituted on the adjacent carbons such as 2-chloroethanol, 2-flouroethanol seem to prefer the gauche configuration. This was thought to be due to hydrogen bonding, but there are related molecules where hydrogen bonding is not a factor that also prefer the gauche form, such as; 1,2-difluoroethane, and 2-fluoroethyl trichloroacetate.

They claim: "There is, as yet, no generally accepted explanation for this behavior"