Question

Draw the structure of the starting material in the ozonolysis reaction below. Hint: The starting material and product have the same number of carbons (i.e., 1 mol reactant : 1 mol product.

Answer 1

Concepts and reason

The product of ozonolysis is given and the reactant that is the starting material needs to be given. The reagent used is ozone in dichloromethane followed by treatment with dimethyl sulfide. Alkenes undergo ozonolysis reaction. Therefore, the starting material can be alkene which undergoes ozonolysis to give the product.

Fundamentals

Ozonolysis: Alkenes on treatment with ozone result in the formation of ketones or carboxylic acid depending upon the type of oxidation undergone. The reductive ozonolysis with Zn/ or leads to the formation of aldehyde or ketones and the oxidative ozonolysis with leads to the formation of carboxylic acids.

Mark the carbonyl positions as shown in the figure.

Join the positions 1 and 5 and substitute the carbonyl oxygen with an alkene to get the starting alkene as shown below:

Ans:

The starting material in the ozonolysis reaction is as shown below: