Answer:
3-phenylprop-2-enal
Explanation:
The given compound consists of a phenyl group, which is the ring
Considering the longest chain starting from the carbon atom closest to the aldehyde, CHO, functional group, the location of the phenyl group is at the 3rd carbon atom on the longest chain
C6H5-C₃H = C₂H - C₁HO
Therefore, for the name of the branched group, we have;
3-phenyl
Based on the location of the double bond, at the second carbon atom, we have;
The name of the straight chin = Prop-2-ene
The name of the aldehyde functional group, CHO, is then added at the end by indicating its position on the longest chain, which is on the first carbon, the IUPAC name of the aldehyde functional group is -al, to give;
1-al
Combining, we get
3-phenylprop-2-ene-1-al
We remove the 1, to get the IUPAC name of the compound as follows;
3-phenylprop-2-enal
