Organic Chemistry Naming Examples 4 Organic Chemistry Naming Examples 4
Organic Chemistry Naming Examples 4
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- Let's see if we can name this guy right here.
- In all of these problems, I guess you can call them, we
- look for the longest chain or the longest ring, and this one
- is pretty obvious here.
- The ring in the middle is clearly the longest carbon
- structure here.
- It has one, two, three, four, five, six,
- seven, eight carbons.
- Let me highlight that.
- It is eight carbons, so we will be you using the prefix
- oct-, and it is in a cycle, so it will be cyclooct-, and it's
- all single bonds, so it's cyclooctane.
- This right here tells us that our core is cyclooctane.
- Now let's look at the different subgroups or the
- different branches off of the main ring.
- Over here, we have a one, two, three, four-carbon group.
- It is in a cycle or it's in a ring, so this is cyclo-.
- Four carbons are but-, cyclobutyl, -yl because it's a
- subgroup or it's off of the main chain or the main ring,
- so that is our cyclobutyl right there.
- We also have another cyclobutyl right here, four
- carbons in a ring, so that's another cyclobutyl.
- Up here, we have three carbons in a cycle.
- The prefix for three carbons is prop-, so this is
- Then down here, let's start with the common names, because
- those tend to be a little bit easier.
- We have one, two, three, four carbons.
- Actually, we have it there and there.
- One, two, three, four, these are the same groups.
- We're going to be dealing with but- if we do common names,
- and you see it has this Y shape.
- We're kind of connected to the base of the Y in either case,
- so we are dealing with isobutyl.
- The Y shape tells us that we're
- dealing with iso-, isobutyl.
- That's both of these right there.
- Now, we have to figure out how we're going to number, where
- we're going to number ourselves on this ring.
- And to do that, we look for the group that is first
- This is a little bit of a confusing point sometimes.
- If this was a tert-butyl or sec-butyl, we would consider
- the B, but when it's isobutyl, it's all considered one word,
- so we'll consider the I.
- We need to compare the I to the C, to the C, to the C, so
- the C's definitely win out on the I.
- If we look at all of these cyclos, cyclobutyl definitely
- takes precedence over cyclopropyl.
- It comes first alphabetically.
- Let's make our starting point this cyclobutyl, although you
- could have made it that cyclobutyl as well, so we'll
- make that our starting point.
- We're going to go in a clockwise direction, so that
- we could get to this one first, so that the next group
- is only going to be a two.
- Otherwise, the next group would have been at three.
- So one, two, three, four, five, six, seven, so this is a
- This is a 6-cyclobutyl.
- This is a 7-cyclopropyl.
- This is a 2-isobutyl, so this is a 2-isobutyl and this is a
- We want to write them all in alphabetical order.
- The cyclobutyls win, so we have a cyclobutyl at one.
- We have a 1-cyclobutyl.
- We also have a 6-cyclobutyl.
- we have two of them, so it is dicyclobutyl.
- Let me capitalize since that's where we're starting.
- So we got those two guys out of the way, and then
- alphabetically, cyclopropyl is next, so then we have a
- Let me do that in that orange color of the cyclopropyl.
- 7-cyclopropyl, got that guy out of the way.
- Then at two and four we have an isobutyl.
- We have a 2,4-, and we have two of them, so it is
- diisobutyl, and then finally cyclooctane.
- We got the 2,4-diisobutyls out of the way, and then we have
- our cyclooctane, so I'll just write the cyclooctane.
- And we're done.
- This was the common naming.
- Now, if we want to do systematic naming, we would
- have to use something else other than the isobutyl.
- And to do that, let me do that over here.
- What you do is you use your connection point as one, and
- you just branch.
- Let me do this in a color I haven't used for before.
- So let's make that our core chain, so that is one, two,
- three, carbons, so it's propyl, and then on the second
- carbon, on the number two carbon that we are attached
- to, you have a methyl group.
- So this is 1-methylpropyl.
- That's what each of these-- that's a 1-methypropyl and
- then that is a 1-methylpropyl.
- Another way to think about, an isobutyl is the same thing as
- a 1-methylpropyl.
- This is the propyl part, and then this right here-- let me
- do that in that color-- that right there
- is the methyl part.
- Oh, sorry, this isn't a 1-methlypropyl.
- Let me be very careful with my numbering.
- This is the one carbon, two carbon, three carbon.
- The methyl comes off of the second carbon.
- So this is a 2-methylpropyl: one, two, three.
- Methyl comes off of the second carbon.
- This is a 2-methylpropyl group.
- And now when we look at it alphabetically, methylpropyl
- still comes after cyclobutyl, so it definitely won't change
- the numbering of things, and so it still would be last. It
- also comes after cyclopropyl.
- If we were to do the systematic naming, it would be
- 1,6-dicyclo-- there's something very strangely fun
- about this-- dicyclobutyl.
- Then you have your cyclopropyl, 7-cyclopropyl.
- It's like a secret code.
- And then you have your-- now, this is interesting.
- You have two of these guys, right?
- Now you don't say di- when you have this kind of more complex
- naming or this systematic naming.
- Instead you use the word bis-, so we have bis-.
- So let me write it.
- We're at two and four, 2,4-bis, this thing.
- I can just bis-(2-methylpropyl).
- So this part right here is the exact part as
- that part right there.
- This the common name.
- This is the systematic naming.
- And then we have our cyclooctane.
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