Question

Which of the following is not an EWG (Electron Withdrawing Group)?

• A. CN
• B. COOH
• C. COOR
• D. OCH$_3$

Hint:

When analyzing functional groups, remember that groups like CN, COOH, and COOR are common electron-withdrawing groups, while OCH$_3$ is a typical electron-donating group.

Answer 1

The Correct Option is D

Electron withdrawing groups (EWGs) are groups that pull electron density towards themselves, making the molecule more electrophilic. The key groups to remember are:
CN (Cyanide): This is a classic electron-withdrawing group (EWG) due to the electronegativity of the nitrogen atom and the triple bond between carbon and nitrogen.
COOH (Carboxyl group): This is another EWG due to the double bond between carbon and oxygen, and the electronegativity of the oxygen atoms. 
COOR (Ester group): The ester group is also electron-withdrawing because of the carbonyl (C=O) group, which is highly electronegative.
OCH$_3$ (Methoxy group): The methoxy group, with an oxygen atom bonded to a methyl group, is actually an electron-donating group (EDG), not an EWG, because the lone pairs on oxygen push electron density towards the ring or carbon backbone.

Thus, OCH$_3$ is not an electron-withdrawing group (EWG); instead, it is an electron-donating group (EDG).