Organic compound naming

[sam0001]

Hello! So this is a hard question. I can't name this compound. The halogen isn't on the longest carbon chain. Suggestions?



CH3CH2CH(CH2Cl)CH2CH2CH2CH3

[Hellrocks]

3-(chloromethyl)heptane

[sam0001]

Thanks! It'd be different if it was another functional group like an OH right?

[DisaFear]

This?

http://en.wikipedia.org/wiki/Hydroxymethyl

First time hearing of these. So would the name be something like 3-hydroxymethly-heptane?
Doubt something like that would be on the VCE syllabus though

[jasoN-]

No, the hydroxy group takes precedence when naming the parent chain, so you would get 2-ethylhexan-1-ol (or 2-ethyl-1-hexanol whatever floats your boat)

[DisaFear]

Would the left hand side of the chain have to be longer for it to be a hydroxymethyl?

[jasoN-]

The only time you'd use hydroxy in the naming system would be if the parent chain has a functional group with higher priority. Examples include ketones, aldehydes, esters, carboxylic acid

e.g. say we had an alcohol group and a carboxylic group
We would name the compound 4-hydroxybutanoic acid, rather than 4-carboxybutanol

If the left hand side of the chain were longer, as you said, you would simply name the parent chain with the longer carbon chain. It would still end with -ol, regardless of the length of either side of the chain.

[Hellrocks]

Correct me if I am wrong, but hydroxymethyl will be named as a substituent because the longest carbon chain contains no primary functional groups.

[jasoN-]

You look for the longest carbon chain CONTAINING the functional group
so a carbon chain of 8 with a 'hydroxymethyl' group at position 4 will be named 2-propyl-1-hexanol RATHER than 4-(hydroxymethyl)octane

[Hellrocks]

I have always done organic chemistry with locating the longest continuous chain first then looking at the functional groups.
Has the IUPAC rules changed?
So locate primary functional group and then locate the longest carbon chain off the primary functional group is the correct method?

[jasoN-]

http://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry#Basic_principles

An example: http://en.wikipedia.org/wiki/Propylheptyl_alcohol
The IUPAC name is 2-propylheptan-1-ol rather than 4-(hydroxymethyl)nonane

It is true that you look for the longest carbon chain, but it must include the highest priority substituent where possible.