Write down the products of ozonolysis of 1, 2-dimethylbenzene (o-xylene). How does the result support Kekulé structure for benzene?

Explanation

o-Xylene may be regarded as a resonance hybrid of the following two kekule structures. Ozonolysis of each one of these gives two products as shown below :

Thus, in all, three products are formed . Since, all the three products cannot be obtained from any one of the two Kekule structures, this shows that o-xylene is a resonance hybrid of the two Kekule structures (I and II)