[danteOne]

Hi,
I am reviewing some nomenclature for the final and I can't figure out this one small detail. When naming diols a vowel is usually added before the diol. What annoys me is that it isn't the same for each carbon chain. How do I know if it is pentadiol vs pentediol or octadiol vs octediol. My book doesn't even mention this and I know I will lose points if I don't learn it.

[AlphaScent]

when naming diols systematically it usually done with a number for each position of the hydroxy group.  like 1,8-octanediol. I have never heard of octadiol or octediol. I am having trouble finding an answer for you.