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GATE 2023 CY – Question 11

Organic Chemistry · Reduction: Catalytic homogeneous and heterogeneous hydrogenation. Metal based reductions using Li/Na in liquid ammonia, magnesium, zinc, titanium, and samarium. Hydride transfer reagents: NaBH4, L-selectride, K-selectride, Luche reduction, LiAlH4 and DIBAL-H. · 1 mark · Multiple choice

The major product formed in the given reaction is

Diagram for GATE 2023 CY question 11
  1. Structure A
  2. Structure B
  3. Structure C
  4. Structure D

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Show answer and explanation

Correct answer: (A) Structure A

Explanation

Low-valent titanium transfers electrons to the two aldehydes and promotes intramolecular pinacol coupling. Formation ofa C–C bond joins the aldehyde carbons intoa six-membered ring; hydrolysis of the titanium diolate gives the cis vicinal diol shownin **A**. Atthese conditions, the keyed product retains both oxygens rather than undergoing full McMurry deoxygenation.