Introduction: An aldol condensation is a base catalyzed reaction between a pair of aldehydes or ketones. The mechanism for these reactions are somewhat complex and will be covered in the lecture course (130A). However, one can easily determine the final product without understanding the meachanism. [Understanding the mechanism for these reactions is important but being able to quickly determine what the final product looks like should aid you immensly in determining the mechanism.]

Problem 1a is an example of an aldol condensation with dehydration. Acetophenone and benzophenone are coupled together yielding an unsaturated ketone. Notice that 1 equivalent of water is lost in this reaction (thus we have the dehydration).

Referring to the above reaction, effectively the oxygen (in red) and the alpha hydrogens (in blue) are removed in the form of water. It is importnant to note that Two alpha hydrogens are removed in these type of reactions.

Determining the outcome of an aldol condensation with dehydration is fairly easy if one uses a systematic method. The following diagram demonstrates how this can be done: