| Atomic grouping |
 |
| Suffix | -al |
| Prefix | oxo |
| Position in chain | only at
end of chain |
| General formula |
CnH2nO |
| Common family name |
aldehyde |
Notes:
- When writing the -al suffix (alkanal) make absolutely sure that it
is distiguishable from -ol (alkanol).
If necessary, PRINT the 'o' or the 'a'.
- Since the suffix (-al) has an initial vowel, the terminal -e of the alkane name is
dropped before the suffix is added.
- The carbonyl group in tha alkanal (aldehyde) family is
always at the end of a carbon chain. It is this feature which makes it
chemically distinguishable from the carbonyl in any other position in
the carbon chain: hydrogen atoms linked to a carbon which is also linked
to an oxygen atom (either singly or doubly) are readily oxidizable.
Thus a major distinguishing feature between these two carbonyl-containing
compounds is that alkanals are readily
oxidized, alkanones are not.
- Since the carbonyl group is at the end of the chain, this is
always position 1 when it is the principle group (i.e. when the suffix is being used)
and the locant is omitted:
pentanal, NOT pentan-1-al.
However, if the oxo prefix is being used, the locant must also be used,
since oxo is used for a carbonyl group anywhere in the chain.
Examples :
| Structure | IUPAC Name | Model |
|---|
 |
methanal (aka formaldehyde) |
|
 |
ethanal |
|
 |
nonanal |
|
 |
3-ethylpentanal |
|
 |
2-bromohexanal |
|
 |
pentanedial |
|
 |
3-oxohexanal |
|
 |
2-ethyl-3-hydroxybutanal |
|
 |
(2E,4Z)-octa-2,4-dienal |
|
|