How many of the following compounds are aromatic according to Huckel’s rule?
[Step 1]:
Huckel rule: Presence of ( 4n + 2 ) π – electrons in the ring where n is an integer (n=0,1,2,…)
[Step 2]:
contain 6 π and 10 π electrons according to Huckel rule. Therefore, these two are aromatic.
[Step 3]:
and contain 4 π, electrons and are not aromatic.