Give the structures of the compounds which on reductive ozonolysis give : (i)propane-1,3-dial(ii)glyoxal and formaldehyde (iii)acetaldehyde, formaldehyde and carbon dioxide.

Give the structures of the compounds which on reductive ozonolysis giv

1.	Give the structures of the compounds which on reductive ozonolysis give : (i)propane-1,3-dial(ii)glyoxal and formaldehyde (iii)acetaldehyde, formaldehyde and carbon dioxide.
Answer» Solution :(i)Since reductive ozonolysis gives only one product i.e., propane-1,3-dial , therefore , the compound must be a cyclic alkene , i.e., cyclopropene, (ii)Since TWO products , i.e., glyoxal and formaldehyde are obtained , therefore , the compound must be acyclic. Further, since glyoxal (OCH-CHO) contains two aldehyde groups , therefore, on either side, there must a=`CH_2` group. Thus , the compound is 1,3-butadiene `underset"1,3-Butadiene"(CH_2=CH-CH=CH_2)underset((ii)Zn//H_2O)overset((i)O_3)to underset"Formaldehyde"(HCHO)+underset"Glyoxal"(OCH-CHO)+HCHO` (iii)Formation of `CO_2` indicates that on either side of this carbon, there is a DOUBLE BOND. Since `CH_3CHO` and HCHO are the two aldehyde obtained, therefore , this carbon is attached to `CH_3CH`= group on one side and `CH_2`=group on the other side. Therefore, the compound is 1,2-butadiene. `underset"1,2-Butadiene"(CH_3CH=C=CH_2)underset((ii)H_2O)overset((i)O_3)to underset"Glyoxal"(CH_3CHO)+O=C=O + underset"Formaldehyde""HCHO"`