Question

Which of the following reactions yield alcohol as the major product:

• A. A, B, C, D, E
• B. A, B
• C. A, B, C, E
• D. B, C

Hint:

Alcohols are commonly formed by {controlled oxidation of alkanes} or {mild oxidation of hydrocarbons}; strong reduction usually removes oxygen completely.

Answer 1

The Correct Option is B

Concept:
Whether a reaction yields an alcohol depends on the nature of the reactant and the reagent used:

Controlled oxidation of alkanes can give alcohols.
Reduction of carbonyl compounds may or may not give alcohols depending on the reagent.
Some reagents convert functional groups into acids or hydrocarbons instead of alcohols.

(A)
Alkane \(+\ \mathrm{KMnO_4}, \Delta\)

Controlled oxidation can form alcohol as the major product.
Hence, alcohol is formed
.
(B)
\(\mathrm{CH_4}\) with \(\mathrm{Cu/O_2}, \Delta\)

Methane undergoes controlled oxidation to give methanol.
Hence, alcohol is formed
.
(C)
Carbonyl compound with \(\mathrm{Zn/Hg,\,HCl}\) (Clemmensen reduction)

Carbonyl group is reduced to \(-CH_2-\).
Final product is a hydrocarbon, not an alcohol.
(D)
Aldehyde with \(\mathrm{HI/Red\ P}\)

Strong reducing conditions convert oxygen-containing groups into hydrocarbons.
Alcohol is not
the major product.
(E)
Aryl bromide \(\xrightarrow{\mathrm{Mg}}\) Grignard reagent \(\xrightarrow{\mathrm{CO_2}}\) acid

Final product is a carboxylic acid, not an alcohol.

Final Conclusion:
Only reactions A and B
yield alcohol as the major product.