How do you find the gauche number?

[noxflos]

In a staggered confirmation of 2,3-dimeythlbutane, how do you find the gauche number? For that matter, how do you find any gauche number for a chair confirmation? I'm having a hard time understanding it through my book's description.

 

[shrumeo]

Hmm, I'm not familiar with the terminology of "gauche number." Perhaps it just means the number of gauche interactions present? Yeah, without drawing a lot of pictures and looking at the bonds this way and that it's tough to see these conformations most of the time. In staggered 2,3-dimethylbutane I see 2 total interactions that I would call gauche. (4 methyl groups to consider, 2 pairs in gauche). Maybe that's the gauche number (2)?

For any chair conformation? I suppose you mean of cyclohexyl rings, I dunno?

You just have to draw the picture out from the perspective that you can see where the interactions for whatever you're talking about are "gauche."

 

[noxflos]

Thank you for your help. I met with my professor and he explained it...it was # of gauche interactions. Again thanks for your help.