11/17/11 - Knoevenagel Condensation

     I again apologize for the short post yesterday due to my midterm induced absence. So today I will try and include a reaction that I was absolutely stumped on last night during the test, and that being the Knoevenagel condensation reaction.  Initially, while studying, it never occurred to me that it would be necessary for me to focus on the names of reactions, which wouldn't get me anywhere in the world of chemistry, but for time restraints I ignored it.  And of course there was a question solely focused on the name of reactions.
     Well to get to the Knoevenagel condensation (image below being that of a general case).  The case is that a carbonyl compound, being either an aldehyde or a ketone, is reacted with an activated hydrogen compound having two electron withdrawing groups in the 1,3 positions making those hydrogens quite acidic.  This is done under a basic catalyzed environment to deprotonate those acidic hydrogens.  After this enolate is formed, it performs an aldol like reaction on the carbonyl compound alleviating a new alcohol group, which is soon dehydrated to form a pi bonded system.

Picture: Wikipedia

Ref:
Emil Knoevenagel (1898). "Condensation von Malonsäure mit Aromatiachen Aldehyden durch Ammoniak       und Amine". Berichte der deutschen chemischen Gesellschaft 31 (3): 2596–2619..