[deutdeut]

If 1-bromoethane is treated with sodium hydroxide solution in ethanol, will the product, ethene or ethanol is the major product?

[english]

What do you know of the competition between SN2 and E2 of tertiary halides?

If tertiary halides cannot undergo SN2 reactions, which reaction do you think a primary halide will more readily undergo?


Is your alkene product formed more energetically feasible than substitution product?  What do you know about alkenes and the resulting stability from surrounding alkyl groups?  How many alkyl groups does the ethene double bond have surrounding it compared to an alkene fromed from the reaction of a tertiary halide with NaOH?  Which is more stable?


It's just an estimated energetics problem.

[deutdeut]

But is that the substituted product ethanol is the major product while the amount of ethene formed is small?

[english]

But is that the substituted product ethanol is the major product while the amount of ethene formed is small?

What do you think.   

You will form both products.  One is considerably more than the other.

[deutdeut]

That means, when a haloalkane reacts with sodium hydroxide solution in ethanol, both the substituted product, alcohol, and elimination product, alkene will be formed, which is the most depends on the experimental conditions?

[english]

That and theoretical conditions.

Ignoring the actual experiment, which do you suppose is in greater yield?

[deutdeut]

The alcohol.

[english]

Right. 


You see why?


Tertiary halide do not undergo SN2 reactions, but do undergo E2 reactions.

So we can predict that primary halides will yield more SN2 product than E2 product, because we get no SN2 product for tertiary halides.

Secondary halides would give us more E2 the stronger the base. 


In this case the base is strong, yes.  But, for reasons we just went through, you get more SN2 product.

This is one way to look at it.

[deutdeut]

But some say that an ether is formed as the substituted product, why?

[english]

I don't see an ether forming in this reaction.  Maybe through an SN1 reaction, but that is impossible here.

Primary alkyl cations are not stable enough to form.

[deutdeut]

But some books say an ether is formed as the substituted product, while the others say that alcohol is the major product as the hydroxide ion attacks the halide, which is true?

[english]

But some books say an ether is formed as the substituted product, while the others say that alcohol is the major product as the hydroxide ion attacks the halide, which is true?

Depends on what kind of halide you have.  If you have a secondary halide, the alcohol formed from NaOH and the halide will react with excess halide to form an ether.

Primary halides cannot synthesize ethers with a weak nucleophile such as an alcohol.

[g c]

Look up "Williamson Ether Synthesis"