Q.(a) Write structural formula of isobutyl alcohol.

Isobutyl alcohol is (CH3)2CHCH2OH; diethyl ether undergoes alpha free-radical chlorination in sunlight; and phenol converted via CCl4/KOH to salicylic acid is then acetylated to Aspirin.

1. Structural formula of isobutyl alcohol: Isobutyl alcohol (2-methylpropan-1-ol): (CH3)2CH–CH2–OH
2. Diethyl ether + Cl2 in sunlight: In diffused sunlight, chlorine reacts with ethers by a free-radical mechanism, substituting a hydrogen atom on the carbon next to the ether oxygen (the alpha-carbon, which is activated by the adjacent O): C2H5–O–C2H5 + Cl2 --(sunlight)--> CH3–CHCl–O–C2H5 + HCl (In excess chlorine, further substitution can occur, eventually giving the fully substituted perchloro compound, but the first/primary product of mono-substitution is 1-chloro-1-ethoxyethane as shown.)
3. Reaction sequence — phenol + CCl4 + 4KOH, then + acetic anhydride: When phenol is treated with carbon tetrachloride and excess (4 mol) alcoholic/aqueous KOH, an ortho-trichloromethyl intermediate is generated at the position ortho to the –OH (activated by it), which is then hydrolysed under the strongly alkaline conditions to a carboxylic acid group. The net product [A] is salicylic acid (2-hydroxybenzoic acid). …