Q.How are the following conversions effected?

Step 1. (i) Benzyl chloride to benzyl alcohol: benzyl chloride, C6H5-CH2-Cl, is a highly reactive benzylic primary halide (the developing positive charge in its transition state is resonance-stabilised by the adjacent ring).

Step 2. Treating it with aqueous NaOH gives straightforward SN2 nucleophilic substitution: C6H5-CH2-Cl + NaOH(aq) gives C6H5-CH2-OH (benzyl alcohol) + NaCl.

Step 3. (ii) Benzyl alcohol to benzoic acid: benzyl alcohol is a PRIMARY alcohol, so a strong oxidant such as acidified KMnO4 or acidified Na2Cr2O7 carries it all the way through the aldehyde stage (benzaldehyde) to the carboxylic acid. …

Apply straightforward SN2 substitution for step (i), then the standard 'primary alcohol to aci …

• Using PCC for step (ii) expecting the final carboxylic acid -- PCC is specifically the MILDER reagent that stops at the aldehyde stage; a st …