Question

The IUPAC name of dimethyl ether is:
(A) Ethoxymethane
(B) Methoxymethane
(C) Methoxyethane
(D) Ethoxyethane

Answer 1

Hint: Dimethyl ether is an organic compound of the ether family. Ethers are defined as a group of organic compounds in which an oxygen atom is bonded to two alkyl or aryl groups. These two groups could be the same or different. To find the correct IUPAC name we need to draw the structure of dimethyl ether.

Complete step by step solution:
The general formula of ether is $$R-O-R$$, where $$R$$ is an alkyl group. According to the attached substituent group ethers are classified into two categories;
Symmetrical ethers: In these ethers, the substituent group attached to the oxygen is same or identical.
Asymmetrical ethers: In these ethers, the substituent groups attached to the oxygen are different.
The Nomenclature of ethers is done in two standard ways:
Common nomenclature
IUPAC nomenclature
The chemical formula of dimethyl ether is $$C_2{H}_{6}O$$. The structure for dimethyl ether is:

The Common nomenclature of ether is done by naming different alkyl or aryl groups bonded to the oxygen atom on either side in alphabetical order and adding the word ether to it in the end. For example, $$C_2{H}_{5}O{C}_6{H}_5$$ will be called ethyl phenyl ether.
In the IUPAC nomenclature, the guidelines are different. According to the rule of IUPAC, naming a substituent group in which more carbon atoms are present is chosen as the parent hydrocarbon. The other substituent group present on the oxygen atom will be named with the prefix “oxy”. For example, $$C{H}_{3}O{C}_2{H}_5$$ will be named as $$1-methoxyethane$$.
In the case of dimethyl ether we can see there are two alkyl groups bonded to the oxygen atom, Hence according to the IUPAC rules substituent group has the same number of carbon atoms. So, it will be called $$Methoxyethane$$.

Hence, Option (B) is the correct answer for the given question.

Note: Ethers are less polar compounds as compared to esters, alcohols, or amines because of the inability of oxygen to participate in the hydrogen bonding due to the presence of bulky alkyl groups on both sides. Dimethyl ether is used as a refrigerant and as a solvent at low temperature.