Nomenclature of ethers
The nomenclature of ethers consists of naming the carbon chains in alphabetical order and ending the name with the word ether (dimethyl ether).
Physical properties
They are compounds of great stability, widely used as inert solvents due to their low reactivity. Crown ethers complex cations by removing them from the medium, allowing the dissolution of salts in organic solvents.
Synthesis of ethers
They are obtained by the reaction of primary haloalkanes and alkoxides, called Williamson synthesis. They can also be obtained by SN1 reaction between alcohols and secondary or tertiary haloalkanes. A third method consists of the condensation of two alcohols in an acidic medium.
This reaction occurs at moderate temperatures if one of the alcohols is secondary or tertiary, in the case that both are primary it requires temperatures of 140ºC.
Cyclic ethers are formed by intramolecular nucleophilic substitution and the most favorable cycles are 3, 5 and 6.
Ethers as protecting groups
The low reactivity of ethers can be exploited to use them as protecting groups. They are very stable in basic and nucleophilic media, which allows the protection of alcohols, aldehydes and ketones by transforming them into ethers. Deprotection is performed in an aqueous acidic medium.
Opening of oxacyclopropanes
Oxacyclopropanes are strained cyclic ethers that undergo ring-opening reactions in both acidic and basic media.