Nomenclature:
Nomenclature in chemistry is a set of rules that provides us with a systematic method to name various compounds. A worldwide accepted set of rules for nomenclature is given by the International Union of Pure and Applied Chemistry. Nomenclature is easy if you get the gist of how to choose a parent chain from a long carbon chain.
Nomenclature of ether strives on an easy concept of this choice. Let’s find out from the basics.
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What are Ethers?
Ether is defined as a class or group of organic compounds that follow the basic structure of oxygen surrounded by an aryl or alkyl groups on both its sides.
Did you know? Earlier ether was used as an anesthetic agent to make people unconscious during a medical procedure.
What is the Formula of Ether?
The general formula of ether:
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Where R and R’ are alkyl or aryl.
(Here, R1= R2 or R1=R2)
Which, in turn, drives us to the classification of ethers.
Did You Know?
Ether helped physicians to get a better idea of human physiology for refining surgical techniques.
Ether is used as a disinfectant before piercing the skin.
How are Ethers Classified?
Before getting into the classification, let’s first check your knowledge about what symmetry is?
In easy words, symmetry is an object when cut vertically from the center show identical two opposite faces.
Based on this concept and the number of carbon atoms in alkyl or aryl groups on both sides of the oxygen atom, ethers are classified as:
Symmetrical Ether:
If R1= R2, then it is known as symmetrical ether. Here, the substituent groups on both sides of the oxygen atom are the same by the formula.
For example:
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As the number of carbons and on the whole substituent groups on both sides of oxygen is the same, it follows symmetry.
Asymmetrical Ether:
If R1≠ R2, then it’s known as the asymmetrical. Here, the substituent groups on both sides of the oxygen atom are different by the formula.
For example:
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As the number of carbons that are the substituent groups on both sides of the oxygen atom is not the same by formula, it doesn’t follow symmetry.
What are the Types of Nomenclature of Ethers?
In easy language, we all speak a local dialect and the other which connects us to the world. The same is the case with nomenclature.
Nomenclature is a way or method of designating names for various compounds.
Here, we’re going to learn the various methods of naming the organic compounds which are as follows:
Trivial/Common Name Nomenclature of Ethers:
In this, we consider the following:
Alphabetical order of alkyl or aryl groups.
The complexity of the formula.
Ends with the prefix 'ether.'
For example:
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Points to Remember:
Here, the substituent groups are methyl and phenyl.
M is alphabetically before P.
There isn’t any branching.
Hence, the common name of ether = Methyl phenyl ether.
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Points to Remember:
Here, substituent groups are isopropyl and ethyl.
E is alphabetically before i.
There is secondary branching in the compound in the alpha carbon.
Hence, the common name of ethers= Ethyl isopropyl ether.
Cyclic Ethers Follow This Below:
Cyclic ether with 2 carbons = Epoxide.
Cyclic ether with 4 carbons with 2 double bonds = Furan.
Cyclic ether with 5 carbons with 2 double bonds = Pyran.
Cyclic ether with 4 carbons with 2 oxygen atoms = Dioxane.
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IUPAC Naming of Ethers:
What are the steps proposed by IUPAC in naming ethers?
The naming of ethers is done in the following steps, the rules underlying the nomenclature of ethers are:
Select the substituent group with the maximum number of carbon atoms.
The substituent group with lesser carbon atoms is written as first words with the addition of ‘oxy’.
When multiple substituent groups are the same, then suffixes like di, tri, etc. are used.
For example:
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Points to Remember:
Here, substituent groups are methyl and ethyl.
Methyl being the one with lesser carbon atoms than the ethyl group, will have the prefix ‘oxy’ attached to it.
There isn’t any branching.
Hence, the IUPAC name of ether = Methoxyethane
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Points to Remember:
Here, substituent groups are methyl and ethyl.
Methyl being the one with lesser carbon atoms than the ethyl group will have the prefix ‘oxy’ attached to it.
There isn’t any branching.
There are two methyl groups adjacent to oxygen atoms.
IUPAC name of ether = Dimethoxyethane.
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FAQs on Ether Nomenclature
1. What are the Uses of Ethers?
Ans: Different uses of ethers are:
Ethers are an Excellent Solvent in Grignard’s Reaction:
As ether is aprotic, they easily dissolve magnesium ions hence easily continue the Grignard reaction. This reaction involves:
R-X + Mg−dry ether → R-MgX
Diethyl ether is the best suited for the formation of Grignard reagents for two reasons.
Acidic protons being absent in ether, so Grignard reagents are stable in ether.
Ether is a great solvating agent.
The Mg-X bond in the reagent is ionic.
In cold weather, ether is used as a volatile starting fluid for engines.
Also used as plasticizers.
Used as a common ingredient for anesthesia in surgery.
Used as a refrigerant.
Phenyl is used as a heat transfer medium because of its high boiling point.
2. What are the Various Properties of Ethers?
Ans: The physical properties of ethers are as follows:
Dimethyl Ether and Ethyl Methyl Ether: Gases at ordinary temperature.
Other Lower Homologs: Have no colour, a pleasant fragrance, and these liquids are volatile.
Ethers have much lower boiling points in comparison to isomeric alcohols.
Ethers with 3 or fewer carbon atoms are soluble in water, due to their hydrogen bond formation with water molecules.
With an increase in the number of carbon atoms, the solubility in water decreases. These are soluble mainly in organic compounds like alcohols, acetone, etc. appreciably.
The chemical properties of ethers are as following:
C-O bond Cleavage: Ethers are unreactive, but in the presence of halogenic acids, there is a cleavage of C-O bond forming alkyl halides.
Electrophilic substitutions: Ether show electronic substitution as,
1. Halogenation
2. Friedel Craft’s reaction
This is due to the activation of ortho and para positions of aromatic compounds by alkoxy groups.