Question

Ozonolysis of o-xylene give:
A.Glyoxal
B.Methylglyoxal
C.Dimethyl Glyoxal
D.All of the above

Answer 1

Hint: The Ozonolysis reaction involves the action of ozone followed by the hydrolysis of the products of alkenes and alkynes. In the reaction, the double and triple bonds are broken to carbonyl compounds.

Complete Stepwise Solution:
The Ozonolysis reaction is an organic reaction in which unsaturated organic compounds such as alkenes, alkynes, azo compounds, are cleaved using ozone to form smaller aldehydes and ketones in case of alkenes, alkynes and aromatics and nitrosamines in case of azo compounds.
In the o-xylene molecule, there are two methyl groups, placed adjacent to each other in a benzene molecule. Due to the action of the ozone molecule the o-xylene molecule is broken apart into three different products. Which are then hydrolysed by zinc and water to form the following products: glyoxal or ethane dial, butan-2,3-dione or Dimethyl Glyoxal, and finally 2-oxopropanal or Methylglyoxal.
Hence, all the answers are correct answers

So the correct option is D, all of the above.

Notes: The Ozonolysis reaction is a very useful way of converting the alkenes and alkynes into aldehydes and ketones, the only problem being that a range of products are formed which are difficult to separate.
In a typical reaction, ozone gas is bubbled through the solution of the alkene or the alkyne taken in methanol at $ - {78^\circ}{\text{C}}$ when the ozonolysis product is formed. This product is then subjected to hydrolysis in presence of zinc metal when we get the desired product.