In Part I, there was an example of a crossed Aldol Condensation leading to a mixture of products where only one may have been desired. The question was raised, how might one implement control over this reaction? It’s important to note the conditions for the reaction between acetaldehyde (Acet) and propionaldehyde (Prop) utilized NaOEt and EtOH as reagents. This particular choice of reagents leads to “thermodynamic control” over the reaction. The greatest synthetic utility of the Aldol Condensation is realized through carefully implemented kinetic control of the reaction conditions at low temperature using lithium diisopropylamide (LDA) or a comparable base for deprotonation.
