Experiments
EXPERIMENT 1: REACTIONS OF ENOLATE IONS WITH CARBONYL GROUPS
Aims
In this experiment we used two techniques for the reactions of enolate ions with carbonyl groups. One technique used was Doebner reaction and the other technique used was Claisen-Schmidt reaction. Therefore the aim of this experiment is to synthesize trans p-methoxycinnamic acid and to synthesize dibenzalacetone via an aldol condensation reaction between acetone and benzaldehyde. The products would be recrystallized using ethanol, then characterized using melting point analysis.
Introduction:
In this experiment we learnt on carbonyl compounds, enols and enolates. We also learnt two different techniques to test the reactions of enolate ions with carbonyl groups which are discussed below.
I. Carbonyl Compounds, Enols and Enolates.
Some of the most suitable reactions of carbonyl compounds contain carbon hydrogen bonds adjacent to the carbonyl group. Such reactions, which can be observed as the strength of much synthetic organic chemistry, usually result in the replacement of the hydrogen by some other atom or group, as in the H-C-C=O -+ X-C-C=O. Transformation of a carbonyl compound to an enol at a suitable rate typically needs either a basic catalyst or an acidic catalyst and, of course, at least one hydrogen on the a carbon.
Even though these reactions lead to numerous varied products subjecting to the reagents and conditions, they have one feature shared- they proceed by way of the en01 or the enolate anion of the parent carbonyl compound as shown below.
II. Knoevenagel Condensation Reaction
The Knoevenagel condensation reaction is an organic reaction named after Emil Knoevenagel. It is a reform of the Aldol condensation. A Knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated (hence condensation). The product is often an alpha, beta conjugated
Aims
In this experiment we used two techniques for the reactions of enolate ions with carbonyl groups. One technique used was Doebner reaction and the other technique used was Claisen-Schmidt reaction. Therefore the aim of this experiment is to synthesize trans p-methoxycinnamic acid and to synthesize dibenzalacetone via an aldol condensation reaction between acetone and benzaldehyde. The products would be recrystallized using ethanol, then characterized using melting point analysis.
Introduction:
In this experiment we learnt on carbonyl compounds, enols and enolates. We also learnt two different techniques to test the reactions of enolate ions with carbonyl groups which are discussed below.
I. Carbonyl Compounds, Enols and Enolates.
Some of the most suitable reactions of carbonyl compounds contain carbon hydrogen bonds adjacent to the carbonyl group. Such reactions, which can be observed as the strength of much synthetic organic chemistry, usually result in the replacement of the hydrogen by some other atom or group, as in the H-C-C=O -+ X-C-C=O. Transformation of a carbonyl compound to an enol at a suitable rate typically needs either a basic catalyst or an acidic catalyst and, of course, at least one hydrogen on the a carbon.
Even though these reactions lead to numerous varied products subjecting to the reagents and conditions, they have one feature shared- they proceed by way of the en01 or the enolate anion of the parent carbonyl compound as shown below.
II. Knoevenagel Condensation Reaction
The Knoevenagel condensation reaction is an organic reaction named after Emil Knoevenagel. It is a reform of the Aldol condensation. A Knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated (hence condensation). The product is often an alpha, beta conjugated
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