The Student Room Group

Functional groups

Looking for someone to double check these prefixes for functional groups (therein assuming they are contained within an organic molecule that has a higher priority group).

Ester: -oxycarbonyl
Acid chloride: chlorocarbonyl
Aldehyde: formyl-

I'm not too sure about aldehyde and I recall reading somewhere that it can actually be "oxo-", however, with consideration to ketones I thought I should go with "formyl".

Any assistance would be greatly appreciated.
Reply 1
I have never seen these prefixes before.

Ester: e.g. ethyl propanoate. Where the carbon that is bonded to ONLY one oxygen comes first (ethyl) and then the rest of the molecule (propanoate) ethyl-propanoate.gif

Acid chloride: e.g. ethanoyl chloride. Basically name the carbon chain making it end in '-oyl' and add the halogen after 'chloride/bromide/iodide'

Aldehyde: e.g. ethanal. Take the carbon chain and end it in ''-al''. (HAHAHAHAHA ethANAL)
Original post by DashStrike
Aldehyde: e.g. ethanal. Take the carbon chain and end it in ''-al''. (HAHAHAHAHA ethANAL)


Reply 3
Original post by addylad


Hahahahahahahahahaha :')
Reply 4
Original post by addylad

Why does this gif look really HD, or is it just me?
Reply 5
Slightly :topic: , but yeah, it's 1020p :')
Reply 6
Original post by DashStrike
I have never seen these prefixes before.

Ester: e.g. ethyl propanoate. Where the carbon that is bonded to ONLY one oxygen comes first (ethyl) and then the rest of the molecule (propanoate) ethyl-propanoate.gif

Acid chloride: e.g. ethanoyl chloride. Basically name the carbon chain making it end in '-oyl' and add the halogen after 'chloride/bromide/iodide'

Aldehyde: e.g. ethanal. Take the carbon chain and end it in ''-al''. (HAHAHAHAHA ethANAL)


Those are suffixes.

What I am talking about is whenever you have say an organic molecule with both an aldehyde and an acid chloride.

As the acid chloride is higher priority it will become the main name and the aldehyde will become the prefix.

The problem is I've saw different prefixes used (oxo-,aldehyde- and formyl-).

Do you get what I mean now?

I just want to be on the safe side if a question requiring me to notice the difference in priority showed up.
Reply 7
Original post by Jargonium
Those are suffixes.

What I am talking about is whenever you have say an organic molecule with both an aldehyde and an acid chloride.

As the acid chloride is higher priority it will become the main name and the aldehyde will become the prefix.

The problem is I've saw different prefixes used (oxo-,aldehyde- and formyl-).

Do you get what I mean now?

I just want to be on the safe side if a question requiring me to notice the difference in priority showed up.


Oooooh right. Sorry I'm not sure about that :s-smilie:
Reply 8
Original post by DashStrike
Oooooh right. Sorry I'm not sure about that :s-smilie:


I can't seem to find any single answer for them, if only IUPAC would make a nice list of all the prefixes, suffixes and conditions..

Things would be a lot easier!

I'll talk to my teacher about it tomorrow.

Thank you for trying anyhow :biggrin:
Reply 9
Original post by Jargonium
I can't seem to find any single answer for them, if only IUPAC would make a nice list of all the prefixes, suffixes and conditions..

Things would be a lot easier!

I'll talk to my teacher about it tomorrow.

Thank you for trying anyhow :biggrin:


IUPAC sucks >:frown: No problem, sorry I couldn't help you more :frown:
From what I know, oxo- is the prefix for ketones, not aldehydes. I suppose having to use prefixes for these functional groups is quite unlikely given how oxidised they are.
Reply 11
Original post by thegodofgod
From what I know, oxo- is the prefix for ketones, not aldehydes. I suppose having to use prefixes for these functional groups is quite unlikely given how oxidised they are.


I got some further information: oxo- is correct for ketones, and in certain circumstances aldehydes also.

They are quite rare, but in terms of exam difficultly that's the type of questions that a limited amount of people will be able to answer - and I'm a big fan of naming organic molecules.. :colondollar:
Check your syllabus - pretty sure on ours, you don't have to know the prefixes for any of the ones you mentioned.

Saying that, I think that oxo- is used for both ketones and aldehydes, as it just refers to the =O. It'd just have a different number. But there are very few functional groups that take priority over an aldehyde. And on my exam board (AQA) you wouldn't be asked a question like that anyway.

Not sure on the others :P
Original post by DashStrike
IUPAC sucks


:rofl::rofl:

you really have nooooo idea of the complexity of the issue, do you?

http://www.chem.qmul.ac.uk/iupac/

Start from here ...
Reply 14
Original post by charco
:rofl::rofl:

you really have nooooo idea of the complexity of the issue, do you?

http://www.chem.qmul.ac.uk/iupac/

Start from here ...


I was only joking :P Although I didn't know there were so many articles, I do know how hard it is to set global standard for a subject as complex as chemistry.

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