Synthesis (c)
a. In the given case, primary alcohol has to be converted into secondary alcohol.
The conversion can be carried out as follows:
Synthesis (a)
The reagent POCl3 , pyridine, is a dehydrating agent and can be used to convert the alcohol to its corresponding alkene.
The reaction of an alkene with H2O,H2SO4 yields secondary alcohol as the OH group adds on the more substituted carbon atom.
b.
Synthesis (b)
The reaction of an alkyl bromide with a strong base yields alcohol as the Br (bromine) group is replaced by the OH (hydroxyl) group.
The dehydration of alcohol yields the corresponding alkene that can be converted into primary alcohol by hydroboration oxidation.
The alcohol can be converted into an alkoxy group by treating it with a strong base followed by a reaction with an alkyl halide (preferably alkyl iodide).
c.
Synthesis (c)
The reaction involves the conversion of alkyl halide into an alkene by the reaction of the alkyl halide with an alkoxy base.
The desired secondary alkyl chloride can be obtained by treating the alkene molecule with hydrochloric acid (Markonikov’s addition).