Why does it not matter whether the OH groups are cis to one another in the furanose ring or trans to one another?
Please help!
I believe it has to do with the mutarotation of the hydroxyl groups in solution.
You can read about furanoses here and mutaroration on the link below that.
http://en.wikipedia.org/wiki/Furanose
http://en.wikipedia.org/wiki/Mutarotation