Answer:
4-Methylpentanal
Step-by-step explanation:
1. Find the longest continuous chain that contains the carbonyl carbon
The longest chain contains five carbon atoms (pentane).
2. Identify the functional group
The functional group is an aldehyde.
You form the name of an aldehyde by dropping the -e from that of the parent alkane and adding the ending -al.
pentane - "-e" + "-al" ⟶ pentanal
3. Number the C atoms of the main chain.
The aldehyde is automatically C1.
4. Identify any substituents
There is a methyl group on C4.
5. Attach the name of the substituent to that of the parent.
The name becomes methylpentanal.
6. Add the locant
The locant is the locating number (4). Join it to the name with a hyphen.
The IUPAC name is 4-methylpentanal.