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GATE 2026 CY – Question 11

Organic Chemistry · Types of Reactions: Nucleophilic and electrophilic substitution reactions (both aromatic and aliphatic). Addition reactions to carbon-carbon and carbon-heteroatom (N and O) multiple bonds. Elimination reactions. Reactive intermediates – carbocation, carbanion, carbenes, nitrenes, arynes and free radicals. Molecular rearrangements. Barton decarboxylation and Barton-McCombie reaction, Hunsdiecker reaction. · 1 mark · Multiple choice

The major product formed in the following reaction is

Oxime of a gem-dimethyl benzocycloheptanone treated with sulfuric acid; four possible products.
  1. Option A in the figure
  2. Option B in the figure
  3. Option C in the figure
  4. Option D in the figure

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Show answer and explanation

Correct answer: (C) Option C in the figure

Explanation

The official product is C. For the acid-promoted oxime transformation, track the group anti to the departing oxime functionality and the resulting fragmentation/cyclization connectivity. The earlier aromatic-capture assignment to D gave the wrong final product.

Official GATE 2026 answer key: https://gate2026.iitg.ac.in/doc/download/2026/Keys/CY_Keys.pdf