Question

The IUPAC name of $C{H}_{3}COO{C}_2{H}_5$ will be:
(A) Ethyl acetate
(B) Ethyl ethanoate
(C) Methyl propanoate
(D) None of the above

Answer 1

Hint: The abbreviation IUPAC stands for, International Union of Pure and Applied Chemistry.
- The IUPAC name of a compound is a name accepted and used worldwide. The name of the above compound has the name of the group which is attached to the oxygen as the prefix.

Complete Solution :
In the question a compound is given and we have to predict its IUPAC name from the given options. The IUPAC has set many rules for the nomenclature for the compounds, which consists of many groups. Now let’s draw the structure of the given compound.

So now let’s analyze which functional group is present in the molecule. The molecule contains ester functional group i.e. R-CO-O-R’. Hence the molecule is an ester and they can be said as the derivatives of carboxylic acid, since esters are formed by replacing the H from –COOH with an alkyl group.
- Now let’s move on to the naming of ester.
- The ester naming consists of two parts- the acid part and the alkyl part.
- Also, the name of the above compound consists of two parts. The first part is the name of the alkyl group which is attached to the oxygen atom. The alkyl chain attached to the oxygen is called ethyl since it has two carbons in the chain. The second word is derived from the carboxylic acid (acetic acid) with the -ic suffix changed to –ate .Acetic acid is also called as ethanoic acid. Thus, the IUPAC name of $C{H}_{3}COO{C}_2{H}_5$ is ethyl acetate.
- Hence the IUPAC name of the above compound is called ethyl acetate.
- And this molecule has a systematic IUPAC name which is ethyl ethanoate.
So, the correct answer is “Option A”.

Note: There is a great chance of getting confused between the preferred IUPAC name and systematic IUPAC name of the compound. The systematic name is the common name and for the compound given above it is ethyl ethanoate and the most commonly used ester whereas its preferred IUPAC name is ethyl acetate. Preferred IUPAC name refers to the name that is preferred by the IUPAC among the other names of the compound and which is set according to certain rules In general, the esters name is named as alkyl alkanoate.