Biomaths Flashcards
(15 cards)
Who was Alexander William Williamson?
Born in London of Scottish parents, became Professor of Chemistry at University College, London in 1849.
What is the Williamson synthesis?
A method for preparing symmetrical and unsymmetrical ethers by reacting an alkyl halide with sodium alkoxide.
What type of reaction is the formation of ether?
A nucleophilic bimolecular reaction (S2) involving the attack of an alcohol molecule on a protonated alcohol.
What are the conditions for the formation of ethers?
The alkyl group should be unhindered and the temperature kept low to favor ether formation over alkene.
Fill in the blank: The reaction follows ______ pathway when the alcohol is secondary or tertiary.
S1
True or False: Dehydration of secondary and tertiary alcohols to give corresponding ethers is successful.
False
What is the result of acidic dehydration of alcohols?
Gives an alkene and is associated with substitution reaction to give an ether.
What is the significance of temperature in ether formation?
Low temperature favors ether formation; high temperature favors alkene formation.
What happens when an alkyl halide reacts with sodium alkoxide?
It produces ethers containing substituted alkyl groups.
Fill in the blank: Ethers having primary alkyl groups are suitable for preparation by ______.
Williamson synthesis
What does the reaction R-X + R-O- Na+ produce?
Ethers
Why is bimolecular dehydration not appropriate for the preparation of ethyl methyl ether?
Secondary and tertiary alcohols lead to elimination over substitution.
At what temperature does ethanol convert to ethene in the presence of sulfuric acid?
443 K
What is the main product when ethoxyethane is formed?
The main product is an ether.
