Q.54. - Organic Chemistry

Question

Question: An unknown compound A of molecular formula ${\mathit{C}}_{\mathbf{10}}{\mathit{H}}_{\mathbf{18}}\mathit{O}$  reacts with ${\mathit{H}}_{\mathbf{2}}\mathit{S}{\mathit{O}}_{\mathbf{4}}$  to form two compounds (B and C) of molecular formula ${\mathit{C}}_{\mathbf{10}}{\mathit{H}}_{\mathbf{16}}$ . B and C both react with ${\mathit{H}}_{\mathbf{2}}$  in the presence of Pd-C to form decalin. Ozonolysis of B forms D, and ozonolysis of C forms a diketone E of molecular formula ${\mathit{C}}_{\mathbf{10}}{\mathit{H}}_{\mathbf{16}}{\mathit{O}}_{\mathbf{2}}$. Identify the structures of compounds A, B, C and E.

Step-by-Step Solution

Answer

Answer

Step 1: Ozonolysis

Ozonolysis reactions include reactions that utilize ozone in order to break the unsaturated bonds present in an alkene. The products obtained in ozonolysis comprise alcohols, carbonyl compounds, etc.

Step 2: Decalin

Decalin can be found in various forms, which include the cis forms and trans forms. The steric interactions are less in the trans form, which makes it more stable.

Step 3: Identifying the structures of compounds A, B, C, and E

The ozonolysis product of compound B is given below.

Ozonolysis product of compound B

 

In order to find the structure B that leads to the given product, the carbonyl carbons of the products are connected via the double bond as:

Structure leading to the compound B

 

Compound B and Compound C reacts with hydrogen in the presence of the Pd catalyst to form decalin. This indicates that the position of double bonds is different in both compounds.

 

Alcohols can combine with sulfuric acid via dehydration reactions to give rise to an alkene. Compound A with molecular formula  $C_{10}{H}_{18}O$ reacts with sulfuric acid to form compound B and compound C.

The reaction of compound A with  $H_{2}S{O}_4$

 

Ozonolysis of compound C leads to the formation of diketone E comprising the molecular formula $C_{10}{H}_{16}{O}_2$ . The chemical reaction can be given as:

Ozonolysis of compound C