Question

The IUPAC name of compound :

$\stackrel{7}{C}{H}_3-\stackrel{6}{C}{H}_2-\underset{C{H}_3}{\underset{|}{\stackrel{5}{C}}H}-\stackrel{4}{C}H=\stackrel{3}{C}H-\stackrel{2}{C}{H}_2-\stackrel{1}{C}HO$

• A. 5-Methylhept-1-en-1-al
• B. 5-Methylhept-3-en-1-al
• C. 3-Methylhept-2-en-1-al
• D. All of the above

Answer 1

Answer: (B)

5-Methylhept-3-en-1-al

The parent compound is an aldehyde with seven carbon atoms and a carbon-carbon double bond between the third and fourth carbon atom.
So, it is named hept-3-en-1-al.

A methyl substituent is present on fifth carbon atom.
Hence, the IUPAC name of the compound is 5-Methylhept-3-en-1-al.

Therefore, the correct option is $B$