Like I said, the hardest part of this one was just figuring out which chain we're going to use as our root chain. So let's go ahead and look at the different possibilities. I could have used this blue chain right here. That would have been one option. If I used that blue one, how many substituents would I get? Two. So I'm just going to say blue equals 2. I could have also used this red one down here. Keep in mind that the red one down there is the same thing as if I would have made it go down this way, like here, because both roads lead to the same place. How many substitutions would that have had? That would have also had two. Lastly, we could have also done this. How many substituents would that have had if I made that my longest chain? That would actually have three. So, it looks like green is going to win, and that is going to be our longest chain. Alright. If you didn't get that as your longest chain, you already got the question wrong. That's why I told you guys to be really careful about which one you pick as your longest chain.
Right. Now we have to figure out which side is going to get number 1 and which side is going to get, I guess, number 5. So is it going to be number 1 here in red or number 1 here in blue? The first thing I do is look at the closest substituents. So blue has a substituent at position 2 and red also has a substituent at position 2. Does bromine beat methyl? No. I'm not even thinking about that yet. I'm just thinking close to substituents, there's a tie. What do I do in the event of a tie? I go to the next substituent. So now I'm going to go to 3, and 3 has a substituent there for blue, but check it out, 3 also has a substituent on this side for red. So we've got that rare situation where there's a perfect tie because the substituents are symmetrical.
Now what I need to do is use the rule to determine the direction, and that's the last rule, which was alphabetical order. Remember this was actually, I think, rule number 2. The last one said if you can't decide then use alphabetical order. So now what I'm going to do is I'm going to erase all this stuff that has to do with closest substituents and I'm just going to say which one is going to win in terms of alphabetical order, bromine or methyl? So now you guys realize that it's going to be bromine.
So that means that my root chain or my parent is going to be pentane. And what are my substituents? Well, my substituents are going to be I'm going to have a 2-bromo, I'm going to have a 3-ethyl, and I'm going to have 4-methyl. Notice that I couldn't use di, tri, tetra because all of these are different, so I can't use those. Now all I have to do is put these in the right order in a big name and I am done. And that's actually just going to be in alphabetical order, which it already is in. So it's going to be 2-bromo-3-ethyl-4-methylpentane. Tricky, right? So I hope that you guys got that. But if you didn't get that, just consider it a learning experience. You need to be very concerned with which one is your longest chain, which direction are you using before you can start actually putting the name together. Alright. So let's go ahead and move on.