Neeti
Last Activity: 9 Years ago
-R groups are meta directing groups. The pull the electrons towards them so the electron density on ortho and para position decreases so in a way the electron density in meta position is greater than ortho and para position hence -R groups are also known as meta directing groups.
You've got to learn the list of -R groups.
Here’s one in order of strength of -R group:
NO2>SO3H>CN>CHO>COR>COX>OCOCOR(anhydride)>COOR>COOH>CONH2.
Please approve the answer if you like it and feel free to ask any other question. I’d be happy to help :)