The Aldol Condensation: Synthesis of Dibenzalacetone

Objective: The benefit of this lab was to acquaint oneself with the fundamentals of the Aldol Condensation reaction by demonstrating the synthesis of dibenzalacetone (trans, trans-1,5-Diphenyl-1,4-pentadien-3-one) through the aldol condensation of acetone with benzaldehyde. The synthesis began by using a strong base to generate the acetone enolate ion. The ketone/enol tautomerization is an equilibrium process that produces little of the enol (ppm or less). However, any enol that formed quickly reacted …

…acetone with the two molecules of benzaldehyde gives dibenzalacetone, otherwise known as 1,5-Diphenyl-1,4-pentadien-3-one. The end product was recrystallized using ethanol. The final weight of my product was .006g. My percent yield was 10.3%, which some may say was less than desired. A melting point was then taken of both my crude product, as well as, my recrystallized product, resulting in identical melting points of 111-112oC, which indicate similar characteristics in my crude and