[NurseIT]

Hi there!

Please help me in naming this formula.

             CH₃CHCH₃
                    |
CH₃CH₂       CHCH₂CH₃
       |            |
       CH₂      CH₂
       |            |
       CH₂CH₂CHCH₃

---------------------
I'm a bit confused because I have located 2 equal parent chains of 10 carbons.
1 parent chain with 3 substituents and 1 parent chain with 2 substituents
which one is the right name?  kindly state to me the IUPAC naming rule that supports the answer.
 

[P]

Compleate guess as I've not done this for ages:--  Would this be 2,5-Dimethyl-3-Ethyl decane ??

[Borek]

I'm a bit confused because I have located 2 equal parent chains of 10 carbons.
1 parent chain with 3 substituents and 1 parent chain with 2 substituents
which one is the right name?  kindly state to me the IUPAC naming rule that supports the answer.

AFAIR you have to select chain that have the largest number of side chains.

[NurseIT]

Compleate guess as I've not done this for ages:--  Would this be 2,5-Dimethyl-3-Ethyl decane ??

Thanks for the reply.  One of my answer is ----> 3-Ethyl-2,5-Dimetyldecane
Ethyl comes first before Methyl (Alphabetically arranged).  Am I right?

[NurseIT]

I'm a bit confused because I have located 2 equal parent chains of 10 carbons.
1 parent chain with 3 substituents and 1 parent chain with 2 substituents
which one is the right name?  kindly state to me the IUPAC naming rule that supports the answer.

AFAIR you have to select chain that have the largest number of side chains.

Sir, what do you mean by side chains?  or largest number of side chains?
So what should I choose then?
a) parent chain with 3 substituent -----> 3-Ethyl-2,5-Dimethyldecane
b) parent chain with 2 sunstituent -----> 2-isopropyl-5-Methyldecane

[Borek]

Sorry if my English is confusing 

side chain = substituent

Trick is, if you have two parent chains of the same length and you choose the one which has more substituents you end - counterintuitively - with simpler name, as substituents are easier to name.

[english]

It will be much easier if you draw a skeletal structure.

You can see the longest chain this way, noting the carbon positions and what substituents lie along the way.

[NurseIT]

Sorry if my English is confusing 

side chain = substituent

Trick is, if you have two parent chains of the same length and you choose the one which has more substituents you end - counterintuitively - with simpler name, as substituents are easier to name.

Thanks a lot Sir Borek.

Is there a site where I could see the IUPAC ruling that will support this contention?

[NurseIT]

It will be much easier if you draw a skeletal structure.

You can see the longest chain this way, noting the carbon positions and what substituents lie along the way.

Thanks K.V.
I've also done that in paper and pencil.  The only problem I facing right now is choosing the which parent chain.  And I need good and correct explanation that will support my answer.  Do you know a site where in I could see the complete IUPAC rules of naming Hydrocarbons? 

[english]

It will be much easier if you draw a skeletal structure.

You can see the longest chain this way, noting the carbon positions and what substituents lie along the way.

Thanks K.V.
I've also done that in paper and pencil. The only problem I facing right now is choosing the which parent chain. And I need good and correct explanation that will support my answer. Do you know a site where in I could see the complete IUPAC rules of naming Hydrocarbons?

The uniqueness and facility of using skeletal structures lies in the fact that you can count the "points" from left to right, or right to left— whichever way leads to the most points is your longest chain.  Now, those points which you did not count along the way become your substituent groups, whose number is associated with the carbon on the chain you just counted.

International Union of Pure and Applied Chemistry nomenclature can be viewed through their parent website.


The index is here.

Specifically, nomenclature for hydrocarbons can be found from this index here.

[Custos]

...and the answer to the specific question being asked is:

IUPAC Rule 2.6 - If chains of equal length are competing for selection as main chain in a saturated branched acyclic hydrocarbon, then the choice goes in series to:

First: (a) The chain which has the greatest number of side chains.
then (b) The chain whose side chains have the lowest-numbered locants.
then (c) The chain having the greatest number of carbon atoms in the smaller side chains.
then (d) The chain having the least branched side chains.