3. Draw all the aldol addition products that are formed when a mixture of acetaldehyde and pentanal is treated with aqueous sodium hydroxide.
4. A reaction, such as described in question 3, which produces a mixture of products is generally not useful for organic synthesis. Suggest a change in the reaction starting materials for question 3 that would produce a single, similar product.
5. Draw a generic mechanism for aldol condensation.
6. The last step for an aldol condensation involves hydroxide acting as a leaving group. As you have learned previously, hydroxide is NOT a good leaving group. What makes this step possible? (i.e. what is the driving force for this step?)
The last step of the aldol condensation goes via a E1-cB mechanism: meaning an alpha-hydrogen (alpha to the carbonyl group) is abstracted forming a conjugate base (enolate ion). This enolate ion can be formed due to the conjugation it can have with the carbonyl carbon. This conjugate base then eliminates the -OH group which is not a good leaving group generally, but here the negative charge forces the -OH group to leave (cause molecules don't like to be charged you know! they wanna quench that and become neutral eliminating the not-so-good leaving group in the process).
Note: Question 5 has been covered with the question 3.
3. Draw all the aldol addition products that are formed when a mixture of acetaldehyde and...
Write all possible products from aldol reaction between: Butanal and Propanal Formaldehyde and Acetaldehyde What is the product for aldol condensation in reaction 7(b) Write reaction for the synthesis of 3-Metyl-2-cyclohexenone using aldol condensation reaction.
How many different aldol addition products can be formed in the reaction of equal amounts of propanal and butanal with aqueous sodium hydroxide at OC? (Consider only constitutional isomer - not stereoisomers.) C1 OOO QUESTION 2 Which of the following is the aldol addition product of butanal in the presence of sodium hydroxide and water? 2-ethyl-3-hydroxyhexanal C2-methyl-2-hydroxyheptanal C 3-ethyl-2-hydroxyhexanal C2-ethyl-2-hydroxyhexanal QUESTION 3 The reaction of benzophenone in a Aldol self-condensation reaction with sodium hydroxide and water gives which product? C...
1. The aldol condensation reaction belongs to a group of reactions characterized by formation of an enolate. For each of the following aldehydes or ketones, draw the enolate ion that forms when treated with a strong base such as sodium hydroxide. If an enolate cannot form, put NR (no reaction). 2. The first step in the aldol addition of acetaldehyde is an acid base reaction (proton transfer). pka = 16 pka = 15 OH a. The pk, for each acid...
a) Draw all of the products obtained from the base-catalyzed aldol condensation reaction between butanal and pentanal(crossed and self) b) Show the half reaction corresponding to the reduction of permanganate ion to manganese dioxide. Show the half reaction corresponding to the oxidation of cyclopentene to 1,2 dihydroxycyclopentane. Add the two half-reactions together to give the overall net ionic equation of the oxidation of cyclopentene to 1,2 dihydroxycyclopentane using permanganate ion. Can anyone help me out?
4. Draw all of the possible Aldol products (B-hydroxycarbonyl) for the following reaction below. Condensation products are not necessary. (3 points) NaOH Aldol Products
4. Draw all of the possible Aldol products (B-hydroxycarbonyl) for the following reaction below. Condensation products are not necessary. (3 points) NaOH Aldol Products .Ph Me H2O Ph Ме
Plz help 4 Draw all of the possible Aldol products (P-hydroxycarbonyl) for the following reaction below. Condensation products are not necessary. (3 points) Ph NaOH H2O Me Aldol Products Me
Practice the Skill 21.15a When the following ketone is treated with aqueous sodium hydroxide, the aldol product is obtained in poor yields. In these cases, special distillation techniques are used to increase the yield of aldol product. Predict the aldol addition product that is obtained, and propose a mechanism for its formation. For the mechanism, draw the curved arrows as needed. Include lone pairs and charges in your answer. Do not draw out any hydrogen explicitly in your products. Do...
pathway, substitution or elimination, will predominate and so a mixture of products is frequently observed. In contrast to the El reaction which involves a carbocation intermediate, the ElcB reaction takes place through a carbanion intermediate. Base-induced abstraction of a proton in a slow, rate-limiting step gives an anion which then expels the leaving group from the adjacent carbon. The reaction is particularly suited to the elimination of substrates which contain poor leaving groups two carbons removed from a carbonyl group....
Organic Chemistry 2 Experimental Outline In its simplest form, the aldol condensation is a self-addition involving two molecules of the same aldehyde or ketone, in the presence of a base, and results in the formation of a new carbon-carbon bond joining the carbonyl carbon of one molecule to the a-position of the second. In many cases - if the reaction conditions aren't sufficiently mild - the initially formed aldol product reacts further in an elimination reaction to give what is...