Write down the products of ozonolysis of 1,2-dimethylbenzene (o-xylene).

How does the result support Kekulé structure for benzene?

o-xylene has the following two resonance structures:-


We can see that all the three products, i.e., methyl glyoxal, 1, 2-demethylglyoxal, and glyoxal are obtained from two Kekule structures. Since all three products cannot be obtained from any one of the two structures, this proves that o-xylene is a resonance hybrid of two Kekule structures represented as I and II above.


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