Ethers have a tetrahedral electron pair geometry around the oxygen atom, with a bond angle slightly greater than tetrahedral. The C-O bond length in ethers is around 141 pm, similar to alcohols. Ethers are commonly prepared via Williamson synthesis, where an alkyl halide reacts with sodium alkoxide to form the ether. This reaction follows an SN2 mechanism. Ethers are relatively inert due to the lone pairs on oxygen, but can undergo reactions under certain conditions, such as electrophilic aromatic substitution at ortho and para positions of aromatic ethers due to increased electron density at these positions.

1. Prepared by – Debadatta Mahapatra MSc Chemistry

5. Structure of ROR: In ethers, the four electron pairs, i.e., the two bond pairs
and two lone pairs of electrons on oxygen are arranged approximately in a
tetrahedral arrangement.
The bond angle is slightly greater than the tetrahedral
angle due to the repulsive interaction between the two bulky (—R) groups.
The C—O bond length (141 pm) is almost the same as in alcohols.

6. 2. Preparations of Ethers by Williamson Synthesis
 Williamson’s synthesis is an important method for the preparation of symmetrical
and asymmetrical ethers in laboratories.
 In this method, an alkyl halide is reacted with sodium alkoxide which leads to the
formation of ether.
 The reaction generally follows the SN2 mechanism for primary alcohol.

8. Chemical Reactions: Ethers are relatively inert compounds despite the presence of oxygen atom
carrying two lone pairs of electrons in their molecules.
 It is because of this reason that these are used as solvents.
 They undergo chemical reactions under specific conditions. Some of the reactions of ethers
are being described as follows:

10. The presence of negative charge at ortho and para positions indicates that
electron density is more at these positions.
Therefore, electrophile is likely to attack on these positions resulting in the
formation of ortho and para substituted products.