The compound that is NOT oxidized by KMnO₄ is: · ABC26OR0537
Subject: Organic Chemistry · Chapter: Organic Synthesis · Topic: Organic Synthesis – General · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Easy
The compound that is NOT oxidized by $\mathrm{KMnO}_{4}$ is:
(a)
(b)
(c)
(d)
Answer
Answer: D ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Only (d), the 4-pyridyl C(OH)Me2, has no benzylic H, so KMnO4 cannot oxidise it. (a) and (b) have a benzylic C–H, and (c) is a secondary alcohol that is oxidised.
Explanation
KMnO₄ oxidises an alkyl side chain on an aromatic (here pyridine) ring only if the benzylic carbon carries at least one H. (a) isopropyl has a benzylic C–H, so it is oxidised. (b) CH(Me)CMe₃ has a benzylic C–H, so it is oxidised. (c) CH(OH)Me is a secondary benzylic alcohol, so it is oxidised. (d) C(OH)Me₂ is a tertiary benzylic carbon with no H, so it is NOT oxidised. Answer: (d).
Study loop for Organic Synthesis