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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: joshphillips1977 on December 08, 2013, 07:04:37 PM

Title: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:04:37 PM

           C
           |
    C-C-C-C-C
           |
           C
I came up with 3-propylpentane, would that be correct?
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:09:28 PM
Find the longest carbon chain.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:11:26 PM
Sorry about that was suppose to have been 5 in the longest chain.
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:15:13 PM
OK 5 carbon chain. What about the substituents?
Title: IUPAC
Post by: joshphillips1977 on December 08, 2013, 07:19:44 PM
      C
      |
      C
      |
   C-C-C-C-C-C
      |     |
      C    C
      |
      C
      |
      C
     
I came up with 2 propyl 2-butyl 4-ethylhexane, but am unsure if this is correct?
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:23:38 PM
It's on the third carbon (so 3-) and there are 3 substituents (so Prop)...

3-prop
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:26:18 PM
No, there are two substituents on that carbon.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:32:05 PM
Ah so then it would be (2-ethyl 2ethyl)
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:35:15 PM
No, where do you get ethyl from, there are only two 1 carbon substituents on that middle carbon. If that makes sense.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:41:08 PM
kind of so what your saying is I count the one to the left and the one to the right but not the carbon that is in the longest chain. So essentially it would be 2-methyl 2-methyl...
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:42:55 PM
CCC(C)(C)CC

is 3,3-dimethylpentane
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:47:58 PM
alright now I am confused
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:49:14 PM
Why?
Title: Re: IUPAC Naming
Post by: Arkcon on December 08, 2013, 07:50:56 PM
joshphillips1977:  I hope you don't mind me merging your two threads on nomenclature.  Once you figure out one, you may have what you need to solve the other.  Sorry if the order is a little screwy for you and everyone else though.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 07:52:28 PM
The Dim
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 07:55:52 PM
you have a C-C-C-C-C chain with a C and a C on the third carbon, a C is a methyl group, that is 3,3-dimethylpentane
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:06:43 PM
Okay sorry I feel stupid, how do you get the 3,3 and the Di?
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:09:31 PM
the numbering, count from one end of the chain, the two methyls (Di) are on the third carbon,
3,3-dimethylpentane, di meaning two!
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:18:40 PM
Okay slap me if I still don't have it. So the carbon on the left is the one substituent and the one on the right is the second not counting the C in the longest chain that puts each one in the Meth group... for example had there been one C on the left and two C to the right it would have been 3-methyl 3-ethylpentane
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:22:35 PM
I say again you have a 5 carbon chain.
C-C-C-C-C on the middle carbon there are two substituents two methyl groups.
the longest chain is 5 C atoms i.e. a pentane, on the middle carbon number 3 are two methyl substituents, i,e, dimethyl.
so you have 3,3-dimethylpentane.
No magic, that's it.



Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:25:54 PM
why the two threes?
  C
      |
      C
      |
   C-C-C-C-C-C
      |     |
      C    C
      |
      C
      |
      C
     
Which makes this one 2-propyl 2ethyl 4methylHexane Right? could I say 2,2,4 propylethylmethylHexane?
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:32:05 PM
No again find the longest carbon chain
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:35:19 PM
the longest chain would be six
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:37:26 PM
No the longest chain is 8.

Back to the other one, the two "3"s, this is because the two substituents are on the same carbon, carbon number 3, hence 3,3-dimethyl.
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:44:39 PM
see picture.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:45:46 PM
Okay so them both being on the 3rd carbon makes sense, two substituents both on carbon 3 and both methyl
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:47:36 PM
Thats correct.
Now what about the other one, look at the picture I posted.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:47:48 PM
Quote from: discodermolide on December 08, 2013, 08:44:39 PM
see picture.
Oh Snap I get what your saying now... so i am gonna try to answer the second one again and repost...
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 08:50:31 PM
Quote from: discodermolide on December 08, 2013, 08:44:39 PM
see picture.

4,6 dimethyl 4-ethylOctane??
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 08:57:10 PM
Not quite it is 5-ethyl-3,5-dimethyloctane.

the substituents go in alphabetical order.
Then the sum of the numbers must be the lowest, that is in your name the substituents are not in alphabetical order, and the numbers add up to 14.
In my name they are in alphabetical order and the sum is 13.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 09:08:41 PM
Awesome I think I got it, I was suppose to have numbered my chain from right to left this time rather than left to right. Thanks!
Title: Re: IUPAC Naming
Post by: discodermolide on December 08, 2013, 09:12:20 PM
My pleasure.
Title: Re: IUPAC Naming
Post by: joshphillips1977 on December 08, 2013, 09:24:16 PM
and if I wanted to express methanol similarly I would do it like: