Question

The correct IUPAC name of the compound is:

(A) 2-cyano-3-oxopentanal
(B) 2-formyl-3-oxopentanenitrile
(C) 2-cyano-1,3-pentanedione
(D) 1,3-dioxide-2-cyanopentane

Answer 1

When more than two functional groups are present in the compound, then we need to find the principal functional group and name the compound accordingly considering the other functional groups as substituent.

Complete step by step solution:
We can see that the given organic compound has three functional groups. So, the compounds in which more than two functional groups are present, we need to find the principal functional group out of them and consider the other functional groups as substituent.
- In order to give IUPAC names to any compound, we first need to identify the functional group present in the compound. We can see that there is an aldehyde, cyanide and ketone functional group present in the compound. According to nomenclature rules, the priority of the given functional groups is cyanide > aldehyde > ketone. So, we will take cyanide group as the principal functional group in the compound and we will take ketone and aldehyde functional group as substituents.
- We will then find the longest chain of carbons that includes the carbon of the cyanide group. We can see that a five member chain is possible. So, we will use pentane as the parent chain.
- We will start numbering from the cyanide carbon and show the substituent groups.
- We can see that in the second carbon, the aldehyde functional group is there. So, we will use the formal prefix for that. At third carbon, ketone is there. So, we will use oxo prefix to show that.
- Thus, we can name this compound as 2-formyl-3-oxo-pentanenitrile

So, the correct answer is (B).

Note: The order of decreasing priority for the principal functional group in multi-functional group compounds is as below.
Carboxylic acid > Sulfonic acid > Ester > Acid chloride > Amide > Cyanide > Aldehyde > Ketone > Alcohol > Amine > Alkene > Alkyne