Williamson Synthesis

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The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol (alkoxide). This reaction was developed by Alexander Williamson in 1850.Typically it involves the reaction of an alkoxide ion with a primary alkyl halide via an SN2 reaction. This reaction is important in the history of organic chemistry because it helped prove the structure of ethers.

Since alkoxide ions are highly reactive, they are usually prepared immediately prior to the reaction, or are generated in situ. In laboratory chemistry, in situ generation is most often accomplished by the use of a carbonate base or potassium hydroxide, while in industrial syntheses phase transfer catalysis is very common. A wide range of solvents can be used, but protic solvents and apolar solvents tend to slow the reaction rate strongly, as a result of lowering the availability of the free nucleophile. For this reason, acetonitrile and N,N-dimethylformamide are particularly commonly used.
A typical Williamson reaction is conducted at 50 to 100 °C and is complete in 1 to 8 h. Often the complete disappearance of the starting material is difficult to achieve,

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