question_answer

\[C{{H}_{3}}CHO+C{{H}_{3}}CHO\xrightarrow{Dil.O{{H}^{-}}}\]\[C{{H}_{3}}CH(OH)C{{H}_{2}}CHO,\]the intermediate in the above reaction is

A)  carbanion          

B)  carbonium ion

C)   carbene            

D)  None of these

Correct Answer: A

Solution :

                 The given reaction is called the aldol condensation and involves the following steps. \[C{{H}_{3}}CHO\xrightarrow[{}]{Dil,.O{{H}^{-}}}\underset{carbainion}{\mathop{\overset{O-}{\mathop{C}}\,{{H}_{2}}CHO}}\,\overset{{}}{\longleftrightarrow}C{{H}_{2}}=CH-{{O}^{-}}\]