Question

The following conversion is carried out using 

• A. hydroboration–oxidation followed by Jones oxidation
• B. Wacker oxidation followed by haloform reaction
• C. oxymercuration–demercuration followed by Jones oxidation
• D. ozonolysis followed by haloform reaction

Hint:

Alkenes → methyl ketones via ozonolysis; methyl ketones → acids via haloform reaction.

Answer 1

The Correct Option is B

Step 1: Observing the transformation.
The starting molecule is an alkene with a methyl substituent.
The final product is a benzoic acid derivative, which indicates cleavage of the alkene and oxidation of a methyl ketone intermediate.
Step 2: First step – Ozonolysis.
Ozonolysis cleaves the C=C double bond into carbonyl fragments.
For this alkene, ozonolysis gives a methyl ketone (Ar–CO–CH$_3$).
Step 3: Second step – Haloform reaction.
A methyl ketone reacts with halogen (Cl$_2$ or Br$_2$) in base to form the haloform reaction product:
Ar–CO–CH$_3$ → Ar–COO$^-$ → Ar–COOH.
Thus the benzoic acid derivative is formed.
Step 4: Eliminating other options.
Hydroboration and oxymercuration do not cleave the double bond.
Wacker oxidation yields acetaldehyde-type fragments but cannot produce benzoic acids from alkenes.
Thus (D) is the only viable pathway.
Step 5: Conclusion.
The conversion is achieved by ozonolysis followed by the haloform reaction.