Question

The IUPAC name of given below structure is

(A) 2-methyl-3-bromo hexanal
(B) 3-bromo-2-methyl butanal
(C) 2-bromo-3-bromo butanal
(D) 3-bromo-2-methyl pentanal

Answer 1

Hint: The parent chain you take during the nomenclature of the compound, needs to have the main functional group present in the compound. The parent chain is made up of five carbon atoms in this compound.

Complete answer:
-See the compound and find the functional groups present in it. The functional group -CHO has the highest priority out of all functional groups present in the compound. That means that we will need to include -CHO group’s carbon atom into the parent chain.
- Let’s determine the parent chain. We have to decide the parent chain in a way that it is the longest chain of carbons possible in the compound and also it should contain a carbon from the main functional group(if the functional group contains carbon atoms).
So,correct parent chain will be

- We should start numbering the parent chain starting from the high priority carbon atom first. Here -CHO carbon has high priority.
Now we will see the substitutions on the parent chain of carbon atoms.
- We can see that there is a methyl group at \[{2^{nd}}\] carbon and a bromine is there at \[{3^{rd}}\] carbon atom in the parent chain. We will use prefixes of both the substitutions to the parent chain and will use the suffix for aldehyde group.
- Also make sure that you mention the substitutions in the alphabetical order.
So, IUPAC name of this compound will be 3-bromo-2-methyl pentanal.
So, correct option is (D) 3-bromo-2-methyl pentanal

Additional Information:
- If there are any substituents present on the parent chain of carbon atoms, then we need to mention them all in the IUPAC nomenclature in alphabetically arranged manner.]
- The numbers that suggest the substitution on the parent chain, needs to be separated by a dash(-) in the name of a compound.
- As we all know that if any aldehyde is present in the compound, then we can use the suffix ‘-al’ after the parent chain name.

Note: Do not forget to include the aldehyde carbon into the parent chain otherwise the name will be incorrect. Always arrange the substitutions in an alphabetical manner and not following that will result in wrong nomenclature.