Question

What is the structure of $4 - oxopentanal$ ?

Answer 1

Hint: In the given name, the word ‘pent’ refers to five Carbons so it is clear to s that the given compound is a five-carbon compound. Now using the IUPAC nomenclature, find out the functional groups associated with the suffix and prefix of the given name.

Complete step-by-step answer:The given structure consists of pent i.e. five Carbons. So the basic chain of the compound is
 $C - C - C - C - C$
Now in the suffix we have ‘-al’ which associates to a carbonyl group, aldehyde. An aldehyde group is basically oxygen attached to a terminal carbon. So now, we attach an oxygen group to one of the two terminal Carbon atoms.
$C - C - C - C - C = O$
So now the Carbon attached to Oxygen becomes the first Carbon in the chain. It is also given that there is an ‘oxo’ group attached to the fourth carbon. The prefix ‘oxo’ associates to a ketone group which is- Oxygen attached to a secondary Carbon.
It is given to us that the ‘oxo’ group is attached to the fourth carbon. We already know that the Carbon in the aldehyde group is first carbon, so now we attach the ‘oxo’ group to the fourth Carbon to get;

We know that Carbon has four valence electrons and forms four bonds, so we can add hydrogens to the rest of the bonds.

Therefore, this is the structure of $4 - oxopentanal$.

Note: The given compound is a substituted aldehyde. It has five carbons and the aldehyde group in one of the terminals. The term ‘oxo’ is a suffix for the ketone group and it is attached to the fourth Carbon. Therefore we substitute the ketone group on the fourth Carbon.