Question

1,2,3,4methyl cyclo butadiene is ant aromatic...how??

Answer 1

It is anti aromatic.

Explanation:

According to the name given by you, the above depicts the compound structure.
Now going by the conditions that qualifies it as an anti aromatic compound

1. It is planar. Since you can see the square butadiene structure in the plane
2. It forms a conjugative system. Clearly there alternate double bonds and single bond in the given compound.
3. It qualifies the rule of having 4n `pi` electrons in the system to be called as an anti aromatic compound. Since each double bond contributes two `pi` electrons to the system, here you have 2 double bonds and hence 4`pi` electrons.

Above conditions makes it an anti aromatic compound.

Hope it helps!!