D & L Glucose: Haworth Formula Explained

[gracy]

In the link given below
http://science.uvu.edu/ochem/index.php/alphabetical/g-h/haworth-formula/
In step 3 last line it is written that 1 and 2 both represent D glucose,but how?As penultimate carbon no 5 has H on right side rather than OH,so it should be L glucose.

 

[Yanick]

It is a rotation around the axis defined by the C4-C5 bond by 60°. Bonds are allowed to rotate, and do so very quickly without changing stereochemistry. Imagine the three substituents on C5 as the legs of a tripod, with the camera or whatnot as the rest of the molecule, and you may be able to see it better.

Refer to this link for an idea about D/L. For what it's worth, I agree with that author about the whole D/L convention. It always annoyed me and I never retained that information beyond whatever exam I needed to know it for.