lab 9 aldol reaction

purpose

perform an aldol reaction b/t benzaldehyde and acetone, then the product will be purified by recrystallization and melting point

Aldol condensation

addition of enolate of one carbonyl group to the other carbonyl group of another

aldol reaction carried out at high temperatures under basic reaction conditions

the aldol can lose the H2O from the alpha and beta carbons and form a,b-unsaturated carbonyl compound

base catalyzed mechanism

acid catalyzed mechanism

chemical reaction

chemicals used

benzaldehyde, acetone, ethanol, and sodium hydroxide

first step (base catalyzed)

aldehyde or ketone deprotonated to form enolate

second step

enolate attacks the carbonyl group to form a tetrahedral alkoxide

third step

B-alkoxide ketone undergoes an acid-base reaction with the removal of the remaining acidic alpha hydrogen and then loss of -oh to give an enone product

base catalyzed aldol synthesis of dibenzalacetone

techniques

ice water bath with stirrer and vacuum filtration using buchner funnel, and TLC