Question

CH2-CO2H 42. $\xrightarrow[\Delta]{Ac_2O}$ ?, Indentify the product.

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

Option (c)

Answer 2

Solution Explanation
The substrate is o‐(carboxymethyl)benzoic acid (a benzene having a –CO₂H and an adjacent –CH₂CO₂H group). Under Ac₂O/Δ conditions the –CO₂H groups are activated (as mixed anhydrides), which promotes an intramolecular reaction. Because one acid group is directly attached while the other is one methylene further, a ring–closure occurs to form a benzofused cyclic derivative. Unlike phthalic anhydride (a five‐membered ring), the extra CH₂ leads to a six–membered ring containing two carbonyl groups (resembling a lactone/diester type ring). This description corresponds to option (c).