Question 13.7:- 

Propanal and pentane-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?

As per the given information, propanal and pentan-3-one are the ozonolysis products of an alkene. Let the given alkene be ‘A’. Writing the reverse of the ozonolysis reaction, we

   H3C-CH2-CHO+CH2-CO-CH2-CH3         PropanalZn+H2O Pentant-3-one                       'X'                     Ozonide                                                  'A'+O3                      Alkene 

 The products are obtained on the cleavage of ozonide ‘X’. Hence, ‘X’ contains both products in the cyclic form. The possible structure of ozonide can be represented as:


Now, ‘X’ is an addition product of alkene ‘A’ with ozone. Therefore, the possible structure of alkene ‘A’ is:

H3C-CH2-CH=C-CH2-CH3                             |                             CH2CH3