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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: jsmith613 on November 30, 2010, 02:52:15 PM

Title: Naming organic compound
Post by: jsmith613 on November 30, 2010, 02:52:15 PM
http://s359.photobucket.com/albums/oo40/jsmith613/?action=view&current=PicChem.png

What is the name of this compound

thanks
Title: Re: Naming organic compound
Post by: rackye on November 30, 2010, 03:21:10 PM
it´s an alkene with six carbon atoms in the principal chain
the double bond is in the carbon number 3
is also the bromine group in the carbon 3 or is the methyl group?
and finally, what kind of oleffine is? a Z one or an E
Title: Re: Naming organic compound
Post by: jsmith613 on November 30, 2010, 03:24:13 PM
I thought It is not an E/Z as I can't work out which side-chain is predominant (surely it would be bromine but then we have 2 ethyl groups so I am confused)

But is it:
E-3-bromo-4-methylhex-3-ene
Title: Re: Naming organic compound
Post by: Fluorine on November 30, 2010, 09:54:39 PM
I got the same name as you did when I tried to name it. Isn't priority based on mass of the substitution? On the left side it's the ethyl and the right side it's the bromine. These two groups are trans of each other so it's E.
Title: Re: Naming organic compound
Post by: rackye on November 30, 2010, 10:03:12 PM
i think you got the right answer
Title: Re: Naming organic compound
Post by: jsmith613 on December 01, 2010, 12:51:39 PM
i think you got the right answer

When I entered this answer into the quiz:
http://www.chembio.uoguelph.ca/educmat/chm19104/nomenclature/quiz1.swf
Quiz 3 question 11 my answer was rejected so I am not sure

thanks
Title: Re: Naming organic compound
Post by: Fluorine on December 01, 2010, 07:20:19 PM
If you drew the molecule correctly try; (3E)-3-bromo-4-methylhex-3-ene

Edit: Your link prompts a download, not sure what to open it with.
Title: Re: Naming organic compound
Post by: jsmith613 on December 02, 2010, 01:54:48 AM
If you drew the molecule correctly try; (3E)-3-bromo-4-methylhex-3-ene

Edit: Your link prompts a download, not sure what to open it with.

no my link goes to a website
Title: Re: Naming organic compound
Post by: Fluorine on December 02, 2010, 02:49:57 AM
In retrospect, I found it works fine in IE but not firefox.
Title: Re: Naming organic compound
Post by: jsmith613 on December 02, 2010, 03:06:29 PM
In retrospect, I found it works fine in IE but not firefox.
Do you know the answer to the original question?
Title: Re: Naming organic compound
Post by: Fluorine on December 02, 2010, 06:57:45 PM
The correct answer as in what the quiz will accept or the proper chemical name for it? I don't know what the quiz wants but ChemSketch confirms the previously given name.

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi54.tinypic.com%2F2nqw0w3.jpg&hash=bde63c96cf959d08c4eebe4e4fbaa806aa0e471a)
Title: Re: Naming organic compound
Post by: rackye on December 02, 2010, 10:49:50 PM
The correct answer as in what the quiz will accept or the proper chemical name for it? I don't know what the quiz wants but ChemSketch confirms the previously given name.

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi54.tinypic.com%2F2nqw0w3.jpg&hash=bde63c96cf959d08c4eebe4e4fbaa806aa0e471a)

totally agree with you  :)
Title: Re: Naming organic compound
Post by: jsmith613 on December 03, 2010, 09:41:12 AM
The correct answer as in what the quiz will accept or the proper chemical name for it? I don't know what the quiz wants but ChemSketch confirms the previously given name.

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi54.tinypic.com%2F2nqw0w3.jpg&hash=bde63c96cf959d08c4eebe4e4fbaa806aa0e471a)

We are talking about

CH2CH3 * 2 with 1 CH3
Not the diagram your using - see first post
Title: Re: Naming organic compound
Post by: sjb on December 03, 2010, 11:34:07 AM
Seems like cis-3-bromo-4-methylhex-3-ene works, but as you have pointed out this is not clear what the cis is referring to. Presumably in this case it means the fact that the two ethyls are on the same side, even though on one end it is higher in priority than the methyl, whilst on the other it is lower than the bromo. That's why E/Z is (usually) straightforward, unless you start talking the enolates of esters, but that's a different story.
Title: Re: Naming organic compound
Post by: Fluorine on December 03, 2010, 07:33:31 PM
We are talking about

CH2CH3 * 2 with 1 CH3
Not the diagram your using - see first post

Either I am misunderstanding or you are. The parent has a hex-3-ene body, H3C-H2C-C=C-CH2-CH3 which gives us C6H10 and two substitutes, a methyl and a bromine, adding up to a total of C7H13Br. Let's ask ChemSketch what the formula of the compound I drew is...


(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi51.tinypic.com%2F10dfrkx.jpg&hash=ac39e338bdf77454e0aaf81334aa8ebd11b6112d)

The carbon and hydrogens are there, just implied. It's not necessary to draw out every single carbon/hydrogen by it's symbol, with a non-mandatory exception when they are terminal/at the end.

Quote from: sjb
Seems like cis-3-bromo-4-methylhex-3-ene works

Do you mean it works in the quiz or naming wise? I can understand how cis/trans could be applied here and why it is incorrect however I cannot seem to get the quiz accept any of the answers for this question.
Title: Re: Naming organic compound
Post by: sjb on December 04, 2010, 04:49:05 AM
Quote from: sjb
Seems like cis-3-bromo-4-methylhex-3-ene works

Do you mean it works in the quiz or naming wise? I can understand how cis/trans could be applied here and why it is incorrect however I cannot seem to get the quiz accept any of the answers for this question.

I meant it was accepted as a correct name on the Flash quiz, posted earlier.
Title: Re: Naming organic compound
Post by: Fluorine on December 04, 2010, 06:26:03 AM
Oh okay, understood. I'm just glad my structure naming isn't as bad as this quiz question led me to believe.
Title: Re: Naming organic compound
Post by: jsmith613 on December 04, 2010, 01:20:33 PM
Quote from: sjb
Seems like cis-3-bromo-4-methylhex-3-ene works

Do you mean it works in the quiz or naming wise? I can understand how cis/trans could be applied here and why it is incorrect however I cannot seem to get the quiz accept any of the answers for this question.

I meant it was accepted as a correct name on the Flash quiz, posted earlier.

It did not work for me?
besides it cant be cis as cis does not account for multiple different sidebranches

I would have said

E-3-bromo-4-methylhex-3-ene
Title: Re: Naming organic compound
Post by: jsmith613 on December 04, 2010, 01:22:01 PM
We are talking about

CH2CH3 * 2 with 1 CH3
Not the diagram your using - see first post

Either I am misunderstanding or you are. The parent has a hex-3-ene body, H3C-H2C-C=C-CH2-CH3 which gives us C6H10 and two substitutes, a methyl and a bromine, adding up to a total of C7H13Br. Let's ask ChemSketch what the formula of the compound I drew is...


(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi51.tinypic.com%2F10dfrkx.jpg&hash=ac39e338bdf77454e0aaf81334aa8ebd11b6112d)

The carbon and hydrogens are there, just implied. It's not necessary to draw out every single carbon/hydrogen by it's symbol, with a non-mandatory exception when they are terminal/at the end.

Quote from: sjb
Seems like cis-3-bromo-4-methylhex-3-ene works

Do you mean it works in the quiz or naming wise? I can understand how cis/trans could be applied here and why it is incorrect however I cannot seem to get the quiz accept any of the answers for this question.

This is wrong there are only 5 carbons not 7
Title: Re: Naming organic compound
Post by: Borek on December 04, 2010, 05:55:16 PM
This is wrong there are only 5 carbons not 7

No, there are six in the longest chain.
Title: Re: Naming organic compound
Post by: Fluorine on December 04, 2010, 09:21:07 PM
It did not work for me?
besides it cant be cis as cis does not account for multiple different side branches I would have said E-3-bromo-4-methylhex-3-ene

Try cis-3-bromo-4-methyl-3-hexene, it worked. It's the same thing SJB wrote except hex-3-ene should be 3-hexene (by the quiz standards).

It can be named by cis but is not recommended by IUPAC with multiple substitution alkenes. This was already discussed and everyone agreed (3E)-3-bromo-4-methylhex-3-ene or E-3-bromo-4-methylhex-3-ene are the correct names for the molecule. For the quiz cis-3-bromo-4-methyl-3-hexene is correct, which is improper but not ambiguous. In other words you could derive the compound from the name using cis-hex-3-ene skeleton.

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi54.tinypic.com%2F2ag67wj.png&hash=24ad95986c96a0e0fc4d637b4f0b8a4cd59c05a9)

This is wrong there are only 5 carbons not 7

Did you understand my reply "The carbon and hydrogens are there, just implied. It's not necessary to draw out every single carbon/hydrogen by it's symbol, with a non-mandatory exception when they are terminal/at the end." or did you simply choose to ignore it? Let me try to explain it visually...

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi56.tinypic.com%2Fehqx5.jpg&hash=aa75a18811526e1a1a9015cbe62a99b49fa81ea8)

Both molecules are hex-3-ene and both have molecular formula C7H13