16.6THE WILLIAMSON ETHER SYNTHESIS

Organic chemistry: “Ethers”. Ethers. Williamson ether synthesis (preparation of ethers via SN2); . Digression on how to remember the -Lowry and Lewis definitions of acids and bases. Cleavage of ethers with (HX). Effect of positive formal charges on reactivity. Effect of acid or base on reactivity.

Williamson ether synthesis - Wikipedia

The Williamson ether synthesis is an organic reaction, ..

Williamson Ether Synthesis Mechanism - Organic chemistry

This page looks at the reaction of aldehydes and ketones with Grignard reagents to produce potentially quite.
Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations This is the Williamson Ether synthesis.
GRIGNARD REAGENT REACTIONS Following is the summary chart of applications of Grignard reagent in modern organic synthesis.

A look at the Williamson ether synthesis mechanism

PMB ethers can be cleavedby –, or .One study employsa benzyl as a benzyl donor foralcohols:The solvent is trifluoromethylbenzene and is an acid .

Benzylmagnesium chloride

Williamson's attempted ether synthesis

Both reactants in the Williamson ether synthesis usually originate in alcohol precursors. Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal, and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4.8), thionyl chloride (Section 4.14), or phosphorus tribromide (Section 4.14). Alternatively, alkyl p-toluenesulfonates may be used in place of alkyl halides; alkyl p-toluenesulfonates are also prepared from alcohols as their immediate precursors (Section 8.14).

The Williamson Ether Synthesis — Master Organic …

diethyl ether.
REACTIONS OF ALDEHYDES AND KETONES WITH GRIGNARD AND RELATED REAGENTS Another possibility for a Grignard synthesis of 2-butanol can be found by 1-butanol.
A student tried to prepare 1-phenylpentane-1,5-diol bya Grignard synthesis using 4-bromo-1-butanol and benzaldehyde.

07/01/2018 · Answer to A Williamson ether synthesis is shown below ..

19/03/2011 · Williamson Synthesis Lab Report

Secondary and tertiary alkyl halides are not suitable, because they tend to react with alkoxide bases by E2 elimination rather than by SN2 substitution. Whether the alkoxide base is primary, secondary, or tertiary is much less important than the nature of the alkyl halide. Thus benzyl isopropyl ether is prepared in high yield from benzyl chloride, a primary chloride that is incapable of undergoing elimination, and sodium isopropoxide:

benzyl ethyl ether could be prepared by a Williamson ether synthesis

PROBLEM 16.7Only one combination of alkyl halide and alkoxide is appropriate for the preparation of each of the following ethers by the Williamson ether synthesis. What is the correct combination in each case?

organic chemistry - Williamson Ether Synthesis - …


Diethyl ether and many others, for example, are prepared by acid-catalyzed reaction of the corresponding alcohols, as we already studuied in alkenes, known as williamson contineous etherification.


In general, this method is limited to the preparation of symmetrical ethers in which both alkyl groups are primary. Isopropyl alcohol, however, is readily available at low cost and gives yields of diisopropyl ether high enough to justify making (CH3)2CHOCH(CH3)2 by this method on an industrial approach.



A method of long standing for the preparation of ethers is the Williamson ether synthesis. Nucleophilic substitution of an alkyl halide by an alkoxide gives the carbon-oxygen bond of an ether.


Preparation of ethers by the Williamson ether synthesis is most successful when the alkyl halide is one that is reactive toward SN2 substitution. Methyl halides and primary alkyl halides are the best reactants (least reactive in elimination).


Secondary and tertiary alkyl halides are not suitable reactants, because they tend to react with alkoxide base by E2 elimination rather by SN2 substitution. Whether the alkoxide base is primary, secondary, or tertiary is not very important than the nature of the alkyl halide. Thus benzyl terbutyl ether is prepared in high yield from benzyl chloride, a primary chloride that is incapable of undergoing elimination, with potassium ter. butoxide (base).


The alternative synthetic route using the sodium salt of benzyl alcohol and an terbutyl halide would be much less effective, because of increased competition from elimination, as the alkyl halide becomes 3° than it easily undergo elimination.

We take some following example also, always prefer alkyl halide as primary.


The alternative combination, cyclohexyl bromide and sodium ethoxide, is not correct, because elimination will be the major product.




Addition of ROH according to marknownikoff’s rule without any molecular rearrangement occurs.