Aldo Condensation
Date: 19th February 2011
Topic: Lab report 03
Synthesis of organic Sun Screen
Introduction:
Aldol Condensation, a useful carbon-carbon bond-forming is the an example of a reaction named based on the type of product formed. This product formed involves two aldehydes or ketones in the presence of dilute base, yields a molecule having both aldehyde and alcohol. The aldol products are β-hydroxyaldehydes or β- hydroxyketones. Condensation reaction is the transformation that result from combination of large molecules to produce another larger molecule. In an aldol condensation, β-hydroxyaldehyde or a β-hydroxyketone is produced in but upon heating the α,β-unsaturated aldehyde or ketone with water is produced. In double mixed aldo condensation of acetone and benzaldehyde, the α-hydrogen’s on both sides of the acetone deprotonates and a nucleophilic enolate anion arises as a result. In an aldol condensation many products are formed there reactant are more than one thus the aldehyde reacts with itself to yield a product. The product formed in an aldol condensation contains and adehydes and an alcohol. Claisen-Schmidt condensation is a crossed aldol condensation that involves an aromatic aldehydes dehydration to yield double bond conjugated aromatic ring and the carbonyl group. Aldol products can dehydrate under either acidic or basic conditions to give, α, β-unsaturated aldehydes and ketones. Although there is even balance in the equilibrium in aldo condensation, the dehydration is usually exothermic. (Wade, 1998)
In crossed aldol condensation careful selection of compound is important to avoid unwanted product mixtures. This is because a crossed aldol condensations is most effective if only one of the reactants can form an enolate ion and the other reactant is more electrophilic toward enolates. Thus Benzaldehyde is a good reagent for crossed aldols because it has no α-hydrogens, so it cannot form an enolate.
In this
Topic: Lab report 03
Synthesis of organic Sun Screen
Introduction:
Aldol Condensation, a useful carbon-carbon bond-forming is the an example of a reaction named based on the type of product formed. This product formed involves two aldehydes or ketones in the presence of dilute base, yields a molecule having both aldehyde and alcohol. The aldol products are β-hydroxyaldehydes or β- hydroxyketones. Condensation reaction is the transformation that result from combination of large molecules to produce another larger molecule. In an aldol condensation, β-hydroxyaldehyde or a β-hydroxyketone is produced in but upon heating the α,β-unsaturated aldehyde or ketone with water is produced. In double mixed aldo condensation of acetone and benzaldehyde, the α-hydrogen’s on both sides of the acetone deprotonates and a nucleophilic enolate anion arises as a result. In an aldol condensation many products are formed there reactant are more than one thus the aldehyde reacts with itself to yield a product. The product formed in an aldol condensation contains and adehydes and an alcohol. Claisen-Schmidt condensation is a crossed aldol condensation that involves an aromatic aldehydes dehydration to yield double bond conjugated aromatic ring and the carbonyl group. Aldol products can dehydrate under either acidic or basic conditions to give, α, β-unsaturated aldehydes and ketones. Although there is even balance in the equilibrium in aldo condensation, the dehydration is usually exothermic. (Wade, 1998)
In crossed aldol condensation careful selection of compound is important to avoid unwanted product mixtures. This is because a crossed aldol condensations is most effective if only one of the reactants can form an enolate ion and the other reactant is more electrophilic toward enolates. Thus Benzaldehyde is a good reagent for crossed aldols because it has no α-hydrogens, so it cannot form an enolate.
In this
References: Masters, K.M.; Minard, R.D.; Williamson, K.L. “Macroscale and Microscale Organic Experiments”, 5th Ed.; Houghton Mifflin Company: Boston, 2007. Monroe, L. “Aldol Condensation”Synthesis of Dibenzalacetone: www.franklincollege.edu/pwp/lmonroe/.../Aldol%20Condensation.pdf, (Accessed 20th February 2011) Wade, G, “ The Aldol Condensation : Synthesis of Dibenazlacetone ” http://www.cerlabs.com/experiments/1087540720X.pdf, (Accessed 18th February 2011) Synthesis of Debenzalacetobe by Aldol Condensation: www2.volstate.edu/chem/2020/.../Aldol_Condensation.html (Accessed February 2011)