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
cyclopropyl.
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
alphabetically.
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
1-cyclobutyl.
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
4-isobutyl.
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
7-cyclopropyl.
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.
Green.
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.