Aldol Condensation Lab
Aldol Condensation
Discussion:
1. Aldol condensation reactions take place in basic conditions, where a deprotonated enol becomes an enolate and proceeds to attack the aldehyde. Since the solution is basic, it is able to deprotonate the alpha carbons of the product, which forces the hydroxide groups to leave. The product is then considered to be dehydrated and unsaturated. In terms of our reaction, cyclopentatone is deprotonated to form an enolate, which then attacks the two molecules of p-tolualdehyde. The result of this attack is a double aldol condensation reaction and the product to be formed is dehydrated.
2. In order to choose the correct solvent, the solvent must not dissolve the solid completely at room temperature. A good solvent will partially dissolve the solid at room temperature and should dissolve the rest of the solid at boiling point. When put in the ice bath it should not dissolve the solid so that the recrystallized product precipitates out of the solution. We choose acetone as our solvent. Acetone was able to dissolve our solid at boiling point and recrystallize it in an ice bath. Hexane was not chosen as the solvent because it would not dissolve the solid at boiling point and Ethanol dissolved the solvent completely at room temperature.
Questions:
2.A) Acetone = contains alpha hydrogen, aldol condensation product:
B) 3- pentanone = contains alpha hydrogen, aldol condensation product:
C) Acetophenone = contains alpha hydrogen, aldol condensation product:
D) Formaldehyde has no alpha hydrogen so aldol condensation is not possible.
E) Benzophenone has no alpha hydrogen so aldol condensation is not possible.
F) Cyclohexanone = contains alpha hydrogen, aldol condensation product:
4. Ketones are less reactive than aldehydes in aldol condensations because the carbonyl group on the ketone is more sterically hindered than the carbonyl group on the aldehyde. This sterical hindrance makes a nucleophilic attack less likely. The
Discussion:
1. Aldol condensation reactions take place in basic conditions, where a deprotonated enol becomes an enolate and proceeds to attack the aldehyde. Since the solution is basic, it is able to deprotonate the alpha carbons of the product, which forces the hydroxide groups to leave. The product is then considered to be dehydrated and unsaturated. In terms of our reaction, cyclopentatone is deprotonated to form an enolate, which then attacks the two molecules of p-tolualdehyde. The result of this attack is a double aldol condensation reaction and the product to be formed is dehydrated.
2. In order to choose the correct solvent, the solvent must not dissolve the solid completely at room temperature. A good solvent will partially dissolve the solid at room temperature and should dissolve the rest of the solid at boiling point. When put in the ice bath it should not dissolve the solid so that the recrystallized product precipitates out of the solution. We choose acetone as our solvent. Acetone was able to dissolve our solid at boiling point and recrystallize it in an ice bath. Hexane was not chosen as the solvent because it would not dissolve the solid at boiling point and Ethanol dissolved the solvent completely at room temperature.
Questions:
2.A) Acetone = contains alpha hydrogen, aldol condensation product:
B) 3- pentanone = contains alpha hydrogen, aldol condensation product:
C) Acetophenone = contains alpha hydrogen, aldol condensation product:
D) Formaldehyde has no alpha hydrogen so aldol condensation is not possible.
E) Benzophenone has no alpha hydrogen so aldol condensation is not possible.
F) Cyclohexanone = contains alpha hydrogen, aldol condensation product:
4. Ketones are less reactive than aldehydes in aldol condensations because the carbonyl group on the ketone is more sterically hindered than the carbonyl group on the aldehyde. This sterical hindrance makes a nucleophilic attack less likely. The