Q16 · CSIR NET Chemistry, December 2013
Paper: CSIR NET December 2013 · Subject: Organic Chemistry · Chapter: Natural Products · Topic: Terpenoids · Marks: 2 · Difficulty: Hard
The major product formed in the sulfuric acid mediated rearrangement of the sesquiterpene saritonin A is 
(a)
(b)
(c)
(d)
Answer
Answer: D ✓ checked by 4AB · confidence medium
The source book printed B; on checking, D is correct — see the explanation.
Explanation
The dienone–phenol rearrangement of santonin in H₂SO₄ gives desmotroposantonin: the angular methyl migrates and ring A aromatises to a phenol bearing two methyl groups — the last structure.
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