Question

How can the following conversions be carried out?
Toluene to benzyl alcohol

Answer 1

Hint: For the conversion of toluene to benzyl alcohol, we can either oxidise the methyl group connected to the benzene ring or either make it feasible for \[O{H^ - }\] to attack the site, which can be obtained from aq. KOH or NaOH.

Complete step by step answer:
> There are numerous methods to convert toluene to benzyl alcohol. I will list here some two unique and beautiful approaches.
> First is by oxidising the methyl group outside the benzene ring to a carboxylic acid and then reducing it to a one-degree alcohol. In this reaction, initially toluene can be reacted with any suitable oxidising agent. For oxidising benzene derivatives, \[KMn{O_4}\] is widely used in a basic medium, followed by adding acidic hydrogens. Now, when toluene is oxidised to Benzoic acid, it can be reduced to Benzyl alcohol using a suitable reducing agent. Lithium Aluminium Hydride is most suitable for the case. The reaction mechanism is demonstrated below:

> Another method is by creating a suitable site for \[O{H^ - }\] nucleophile to attack, which can be obtained from aq. KOH or NaOH. This can be achieved by creating a suitable leaving group outside the benzene ring. Toluene can be chlorinated in presence of light to form Benzyl chloride. Then, benzyl chloride can be reacted with \[O{H^ - }\] and heat to form Benzyl alcohol. The reaction mechanism is:

Note:
1- I have used some common and basic reagents in the above mechanisms. Benzyl alcohol may also be obtained by oxidation of Toluene to Benzoic acid, then treating it with \[SOC{l_2}\] to produce benzoyl chloride.
2- Then, react with benzoyl chloride with \[O{H^ - }\] and heat to obtain benzaldehyde. Then benzaldehyde can be reduced to benzyl alcohol using LAH.