Question

IUPAC name of the compound is :

$C{H}_3-\underset{OC{H}_3}{\underset{|}{C}H}-\stackrel{\text{O}}{\stackrel{||}{C}}-\underset{C{H}_3}{\underset{|}{C}H}-O-C{H}_2-C{H}_3$

• A. 1-ethoxy-3-methoxy-1-methylbutan-2-one
• B. 2-ethoxy-4-methoxypentan-3-one
• C. 2-ethoxy-3-methoxypentan-3-one
• D. none of the above

Answer 1

The correct option is B 2-ethoxy-4-methoxypentan-3-one

There are two functional groups in this compound, one is ether the other is ketone. So by the priority table, the first priority is given to the ketone group, therefore ketone will be the parent functional group and ether will be the substituent.

Now, there are two substituents, one is methoxy and the other is ethoxy, so while numbering ethoxy will get the least number.

Hence start the numbering from carbon, which is next to carbon attached to the ethoxy group. substituents - CO will come at 3rd position and methoxy group at 4th position.

$\stackrel{5}{C}{H}_3-\underset{OC{H}_3}{\underset{|}{\stackrel{4}{C}}H}-\stackrel{\text{O}}{\stackrel{3||}{C}}-\underset{C{H}_3}{\underset{1|}{\stackrel{2}{C}}H}-O-C{H}_2-C{H}_3$

Therefore, the correct option is $B$