Menthol, isolated from various mint oils, is used in the treatment of minor throat irritation. Draw both chair conformations of menthol and indicate which conformation is lower in energy.
Alright guys. So, here's our compound and what we're going to do is convert it into a chair conformation, right? And remember that there's two different chairs that we can draw, so we're going to draw both equivalent chairs and see which one's going to be lower in energy, right? Which one's going to have the lower energy? Well, what's that asking? is asking which one is going to have the greater stability, okay? So let's first draw out our chairs, we know that we can have one chair that looks like this, right? And we can also do a chair flip of that, so that other chair will look like this, where here notice that we have going down and up, so we can get another chair that looks a little bit like this, right? if we connect the corners, okay? So let's figure out which chair is going to be the one that has the smaller energy first what we need to do is, let's just label all these, give them different numbers, right? Nothing to do with naming or anything and identify those numbers over here, right? The same thing here, so let's draw anywhere our substituents there, in the first chair, we can show that at one they can have a substituent going up and at three we could have one also going up, okay? So they're both axial and then the next one is going to be that isopropyl group, right? The one that's on the dash this was an alcohol and now when we know it needs to be facing the other direction and at carbon four, so the other direction is going to be down, okay? So, does that one look stable, all of our groups are axial, we know that for chairs it's more stable to have our group equatorial, so you should be thinking that this one's going to have the higher energy, right? this is going to have a higher energy because when we do a chair flip you guys should realize that we're going to flip all axials to equatorial. So, here in our next chair at one we're going to have a methyl going up at 3 we're going to have an OH going up as well but equatorial and at four, let's take a look, we have an isopropyl but it used to face the other direction, so it's going to look like that, just all of my groups equatorial, so what does that mean? we're just going to have the lower energy and why is that guys? because it has the greater stability, okay? So, keep in mind the stability and energy are inversely related to each other and hopefully you guys remember how to do a chair flip and how to convert our ring here to these chairs and show that both of the chairs are equivalent just doing a chair flip between them switching our groups. Alright guys, so hopefully this makes sense our answer here again is going to be this one round here, this one has a lower energy hence it's more stable. Alright guys, hopefully that made sense.