Williamsons ether synthesis
Again, not ideal.
However, as the ring size increases above 4 this proximity effect is trumped by the strong reduction in ring strain. However, the reason why ring formation does not follow this trend is because of another factor called the proximity effect.
Williamson ether synthesis procedure
Clearly the Williamson is out. Do you notice something wrong here? Conditions[ edit ] Since alkoxide ions are highly reactive, they are usually prepared immediately prior to the reaction, or are generated in situ. Organic Chemistry: Structure and Function. The alcohol that supplies the electron rich alkoxide can be used as the solvent, as well as dimethyl sulfoxide DMSO or hexamethylphosphoric triamide HMPA. First of all, it goes without saying that the base must be strong enough to actually deprotonate the alcohol. Peter C.
We typically start with a flask of our alcohol solvent, add base, and then add our alkyl halide. We need a nucleophile alkoxide and an electrophile alkyl halide to combine in a substitution reaction to form diethyl ether.
Williamson ether synthesis elimination vs substitution
The SN2 is a reaction that is only effective on sp3 hybridized carbon atoms. So what do we do? Five and six membered rings have less strain allowing them to form faster. This should be no surprise, since a backside attack on a tertiary alkyl halide encounters tremendous steric hindrance. It might help to reflect on how these reactions are run. The intramolecular reaction of halohydrins in particular, gives epoxides. We need a nucleophile alkoxide and an electrophile alkyl halide to combine in a substitution reaction to form diethyl ether. Scope[ edit ] The Williamson reaction is of broad scope, is widely used in both laboratory and industrial synthesis, and remains the simplest and most popular method of preparing ethers.
What might happen? Peter C.
How can we do this the right way?
based on 77 review