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GATE 2023 CY – Question 31

Organic Chemistry · Stereochemistry: Chirality and symmetry of organic molecules with or without chiral centres and determination of their absolute configurations and optical purity. Relative stereochemistry in compounds having more than one stereogenic centre. Homotopic, enantiotopic and diastereotopic atoms, groups and faces. Conformational analysis of acyclic and cyclic compounds. Geometrical isomerism and optical isomerism. Configurational and conformational effects, atropisomerism, and neighbouring group participation on reactivity and selectivity/specificity. Stereoselective and stereospecific synthesis. Enantiomeric excess. · 1 mark · Multiple select

The acetolysis product(s) of the given reaction is(are)

Diagram for GATE 2023 CY question 31
  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; (C) Structure C

Explanation

Neighbouring phenyl participation in ionization creates a bridged phenonium ion rather than a free localized carbocation. Acetate opens the bridge with stereospecific backside attack at either equivalent end. The allowed overall stereochemical products are the enantiomeric pair **A, C**; B/D would require the other relative configuration.