Q24E - Organic Chemistry (Mcmurry)

Question

Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common?

Step-by-Step Solution

Answer

a.

b.

c.

d.

Step 1: Reaction of ether with an alkyl halide

Ethers show nucleophilic substitution reaction with alkyl halide either SN₁ or SN₂  depend upon the substrate if the primary and secondary ether is given then the reaction is followed by the SN₂   formation of alcohol and halide occur.

If the ether is tertiary then the reaction is followed by SN₁  formation of the alcohol and alkene occur followed by carbocation formation.

Step 2: Reaction of compound A

As per the given compound the one side of oxygen have a tertiary group is present and the other is primary so it is clear that the reaction proceeds from SN₁ mechanism that the Br^- ion is attacked from the primary side which is ethyl and the formation of ethanol occurs and the tertiary carbocation is formed which followed by E2 elimination and form alkene as shown below:

Step 3: Reaction of compound B

Reaction of ether with alkyl halide formation of alkene and halide when tertiary group attached with oxygen atom and here, also as per SN₁ mechanism Br attack from phenyl side and form phenol and tertiary carbocation which turned to alkene on E2 elimination as shown below:

Step 4: Reaction of compound C

Ether oxygen is attached with the tertiary and secondary group so follow SN₁

mechanism and attack of Br ion occur from secondary less hindered side and formation of the propan-2-ol and tertiary carbocation is formed which further lead to E2 elimination and formation of alkene takes place as shown:

Step 5: Reaction of compound D

As per the product given the reaction is followed SN₁ mechanism and attack occur from the primary group and formation of ethanol occurs and carbocation formation  occur which is followed by E2 elimination alkene formed as given below:

Formation of alkene and alcohol