JEE Main Chemistry question

[IIT 2006] A cyclic lactone bearing an *ortho*-acetoxy (–OCOCH₃) group adjacent to an acetyl (–COCH₃) substituent, on heating with alkali followed by acid hydrolysis, can be obtained starting from which of the following?

(A)The benzene ring bearing an *ortho*-acetoxy (–OCOCH₃) group next to an acetyl (–COCH₃) groupCorrect
(B)The analogous ring with free –CHO and –COCH₃ groups (no ester present)
(C)The analogous ring with –COCH₃ at both positions (no ester present)
(D)The analogous ring with a free –COOH group adjacent to –CHO

Answer: (A)

Solution

Base (alkali) first hydrolyses the aryl acetate to the free phenolate, which is positioned to undergo an intramolecular aldol/Claisen-type condensation with the adjacent ketone's enolate,

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Question ID VK-140139