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GATE 2023 CY – Question 32

Organic Chemistry · Biomolecules: Structure, properties and reactions of mono- and di-saccharides, physicochemical properties of amino acids, chemical synthesis of peptides, chemical structure determination of peptides and proteins, structural features of proteins, nucleic acids, lipids, steroids, terpenoids, carotenoids, and alkaloids. · 1 mark · Multiple select

Product(s) formed in the given reaction is(are)

Diagram for GATE 2023 CY question 32
  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; (B) Structure B; (C) Structure C

Explanation

Base converts free hydroxyl groups into alkoxides. The neighbouring and appropriately positioned remote alkoxides can each displace the C3 tosylate intramolecularly with inversion, forming 2,3-,3,4-and 3,6-anhydro derivatives. These correspond to **A, B, C**. D depicts direct methoxy substitution with retention at the leaving-group carbon, so it is not the accepted product.