Draw skeletal structures for the following:
e. 2-methyl...

Question

Draw skeletal structures for the following:

e. 2-methyl-4-(1-methylethyl)octane

Accepted Answer

Hey, everyone, let's solve this problem. It says give the appropriate ie pack name for each of these compounds. So if you're really good at these, you might be able to use the condensed formula to count the carbons and write the name. But it might be tricky to get the correct number of carbons in the parent in the longest continuous carbon chain because of the substituent group. So it's more helpful to just draw out the compound. So first we connect the carbons from left to right and then we will add the hydrogens and in our condensed formula formula, the hydrogens are written right after the carbon they're attached to. Then we can start naming. So first, you will find the longest continuous carbon chain, OK? Which might include carbons from substituent groups. So that's why we draw it out. And when you count the number of those carbons, you will be able to create the parent chain name. Then once you have how many carbons, you will actually number the carbons, number the chain and you want to start by the end that has more substituent groups, right? Because we want our substi substituent groups to have the lowest number they can. So you'd rather have two methyl than four ethyl if you can number it from either way. And then once we have our substituent groups numbered, we are going to take the number and the name of those substituent groups and we put them in front of the parent chain. I put them in front of the parent chain name. And do we do that in numerical order? No, an alphabetical order, right? Alphabetical order. I know it's tempting to go in numerical order but make sure it's alphabetical. All right. So let's get to it. Give myself lots of room to draw these out. So first we have CH 32 Chch two ch two CH three. So let's connect our carbons again. I start with carbons that are not in substituent groups. So since this carbon is, th these metal groups are in parentheses, I know those two methyl groups are attached to this carbon. So I'm gonna write four carbons first. Oops, let's do black 1234. Then I'll add my two methyl groups. OK. And then we'll add the hydrogens ch three ch three chch two CH two CH three. OK. Now count, find the longest continuous carbon chain. So we can include one of these methyl groups, right? 12345 will give us the parent chain name P A, right? There's only single bond. So it's an Alcaine. And if we actually number it 1 to 5. We wanna start from which end this end, right? Because it's closer to this methyl group. So we have 12345 because if we number it, this way, we'd have 1234 methyl, but we want, we would rather have two methyl. So two methyl is gonna go in front of Pentane. Oh, I forgot my dash. Right. We separate the numbers in the words to methyl. pentane. And that is it for that name, right? Moving on our next one is Ch three ch two. Oops. Not like that. They gave us ch three ch two cch 32 ch two. Ok. So I have 1234 carbons and then those two methyl groups are substituent groups. So let's write the four carbons 1st 1234. And then we'll add our substituent groups to that second carbon from the right. So carbon carbon, we'll add the hydrogen ch three ch two ch three ch three ch two. That's a three. That doesn't make sense, right? We know our Valan rules. Sorry about that. Ok. So let's find our longest continuous carbon chain. Well, this carbon has three methyl groups. So that's the same number of carbons going in each direction. So it doesn't matter which one we start from, but we can start with one of those methyl groups. So how about we just start over here? 1234 and this would give us methro Butane, right? And why did I number it from right to left instead of left to right? Because that gives us methyl's on carbon two rather than 123, right? The lower number. So I have two methyl groups on carbon two. So that is 22 di methyl Beauty. All right. Last but not least. The grand finale, we have Ch three ch two ch two, ch two Chch two ch three ch ch 32. OK. Don't get intimidated. So again, count the carbons that are not in the substituent groups. 1st 123456. So let's draw six carbons attached to each other. 123456. Now let's add the substituent group carbon. So we have two methyl groups on the end in an group on the next carbon in. Hm, let me draw them the other way. So I have more room. OK. Now let's add the hydrogen ch three ch two ch two ch two ch ch two ch three chch three ch three. OK. Now longest continuous carbon chain. Well, which carbon do I stir from if I have this ethyl group, 1234567. OK. What about these methyl groups? Those are both seven as well. 12345671234567. We would rather have more substituent groups than name this single, more bulky substituent group. So we're going to leave the ethyl as a substituent group and start from one of these methyl groups. So 1234567 gives us Heptane. Oh, that's kind of far. Let me do it down here. And again, why did I start numbering right to left? Because that's closer to these two substituent groups, right? Which the substituent groups are two methyl and three ethyl, right? Two carbons. That's ethyl. So which order do I write them? Alphabetical? So, ethyl comes first three ethyl, two methyl hept. All right. I hope this was helpful. Thank you for watching.

Draw skeletal structures for the following:
e. 2-methyl-4-(1-methylethyl)octane

Key Concepts

Skeletal Structures

IUPAC Nomenclature

Substituents and Branching

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