Question

Which one of the carbanions is the least stable?

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

Carbanions are stabilised by electron-withdrawing groups (e.g., \( -\text{NO}_2 \), \( -\text{CHO} \)) and destabilised by electron-donating groups (e.g., \( -\text{CH}_3 \)).

Answer 1

The Correct Option is C

Electron-withdrawing and electron-donating groups attached to the carbanion's carbon atom influence its stability. Electron-withdrawing groups like \( -\text{NO}_2 \) and \( -\text{CHO} \) stabilize the negative charge. Conversely, electron-donating groups such as \( -\text{CH}_3 \) destabilize it. Therefore, a carbanion in \( \text{CH}_2-\text{CH}_3 \), lacking electron-withdrawing groups, exhibits the lowest stability. Final Answer: