question_answer

                An ester (A) with molecular formula \[{{C}_{9}}{{H}_{10}}{{O}_{2}}\] was treated with excess of \[C{{H}_{3}}MgBr\] and the complex so formed was treated with \[{{H}_{2}}S{{O}_{4}}\] to give an olefin (B). Ozonolysis of (B) gave a ketone with molecular formula \[{{C}_{8}}{{H}_{8}}O\] which shows +ve iodoform test. The structure of (A) is:                       

A)                 \[{{C}_{6}}{{H}_{5}}COO{{C}_{2}}{{H}_{5}}\]       

B)                 \[{{C}_{6}}{{H}_{5}}COO{{C}_{6}}{{H}_{5}}\]       

C)                 \[{{H}_{3}}COC{{H}_{2}}CO{{C}_{6}}{{H}_{5}}\] 

D)                 \[p-{{H}_{3}}CO-{{C}_{6}}{{H}_{4}}-COC{{H}_{3}}\]

Correct Answer: A

Solution :

                                \[{{C}_{6}}{{H}_{5}}-\underset{\begin{smallmatrix}  | \\  C{{H}_{3}} \end{smallmatrix}}{\mathop{C}}\,=C{{H}_{2}}\xrightarrow{{{O}_{3}}/{{H}_{2}}O}{{C}_{6}}{{H}_{5}}-\underset{\begin{smallmatrix}  | \\  O  \\  ({{C}_{8}}{{H}_{8}}O) \end{smallmatrix}}{\mathop{C}}\,-C{{H}_{3}}\]                 \[{{C}_{6}}{{H}_{5}}-\underset{\begin{smallmatrix}  || \\  O \end{smallmatrix}}{\mathop{C}}\,-C{{H}_{3}}\xrightarrow[NaOH]{{{I}_{2}}}\,\underset{\text{Iodoform}}{\mathop{CH{{I}_{3}}}}\,+{{C}_{6}}{{H}_{5}}COONa\]