An organic compound $\mathrm{A}(\mathrm{C}_{6}\mathrm{H}_{6}\mathrm{O})$ gives dark green colouration with ferric chloride. On treatment with $\mathrm{CHCl}_{3}$ and KOH, followed by acidification gives compound B. Compound B can also be obtained from compound C on reaction with pyridinium chlorochromate (PCC). Identify $\mathrm{A}$, B and C.

(D) A = (see structure), B = (see structure), C = (see structure)

(A) A = (see structure), B = (see structure), C = (see structure)

(B) A = (see structure), B = (see structure), C = (see structure)

(C) A = (see structure), B = (see structure), C = (see structure)

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Alcohols Phenols and Ethers

An organic compound

A (C_{6} H_{6} O)

gives dark green colouration with ferric chloride. On treatment with

CHCl_{3}

and KOH, followed by acidification gives compound B. Compound B can also be obtained from compound C on reaction with pyridinium chlorochromate (PCC). Identify

A

, B and C.

(A)A = (see structure), B = (see structure), C = (see structure)
A
B
C
(B)A = (see structure), B = (see structure), C = (see structure)
A
B
C
(C)A = (see structure), B = (see structure), C = (see structure)
A
B
C
(D)A = (see structure), B = (see structure), C = (see structure)
A
B
C
✓ Correct

Answer: (D)

Solution

A dark green colouration with ferric chloride is the test for a phenolic hydroxyl, and the formula

C_{6} H_{6} O

fixes A as phenol. Phenol with

CHC l_{3}

and KOH followed by acidification is the Reimer-Tiemann reaction, in which the dichlorocarbene generated from chloroform and hydroxide attacks the position ortho to the hydroxyl group, so B is 2-hydroxybenzaldehyde. Pyridinium chlorochromate oxidises a primary alcohol only as far as the aldehyde, so the compound C that gives the same aldehyde is 2-hydroxybenzyl alcohol. Thus A is phenol, B is 2-hydroxybenzaldehyde (salicylaldehyde) and C is 2-hydroxybenzyl alcohol.

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Single correct option

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JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Alcohols Phenols and Ethers

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