FIGURE 23.2 MECHANISM -

The general mechanism of a carbonyl condensation reaction. One partner becomes a nucleophilic donor and adds to the second partner as an electrophilic acceptor. After protonation, the final product is a $\beta$-hydroxy carbonyl compound.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0815.jpg?height=161&width=291&top_left_y=467&top_left_x=1161)
(1) A carbonyl compound with an $\alpha$ hydrogen atom is converted by base into its enolate ion.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0815.jpg?height=80&width=79&top_left_y=654&top_left_x=1191)
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(2) The enolate ion acts as a nucleophilic donor and adds to the electrophilic carbonyl group of a second carbonyl (2 \| compound.
(3) Protonation of the tetrahedral alkoxide ion intermediate gives the neutral condensation product and regenerates the base catalyst.
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(3) $\downarrow$ New C-C bond
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0815.jpg?height=190&width=434&top_left_y=1393&top_left_x=1198)


FIGURE 23.2 MECHANISM -

A $\boldsymbol{\beta}$-hydroxy
carbonyl compound


FIGURE 23.2 MECHANISM -

Aldehydes and ketones with an $\alpha$ hydrogen atom undergo a base-catalyzed carbonyl condensation reaction called the aldol reaction. For example, treatment of acetaldehyde with a base such as sodium ethoxide or sodium hydroxide in a protic solvent leads to rapid and reversible formation of 3-hydroxybutanal, known commonly as aldol (aldehyde + alcohol), hence the general name of the reaction.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0815.jpg?height=386&width=1229&top_left_y=1948&top_left_x=445)


FIGURE 23.2 MECHANISM -

3-Hydroxybutanal
(aldol-a $\beta$-hydroxy carbonyl compound)
The exact position of the aldol equilibrium depends both on reaction conditions and on substrate structure. The equilibrium generally favors the condensation product in the case of aldehydes with no $\alpha$ substituent
$\left(\mathrm{RCH}_{2} \mathrm{CHO}\right)$ but favors the reactant for disubstituted aldehydes $\left(\mathrm{R}_{2} \mathrm{CHCHO}\right)$ and for most ketones. Steric factors are probably responsible for these trends, since increased substitution near the reaction site increases steric congestion in the aldol product.


FIGURE 23.2 MECHANISM -


WORKED EXAMPLE 23.1 -


Predicting the Product of an Aldol Reaction -

What is the structure of the aldol product from propanal?


Strategy -

An aldol reaction combines two molecules of reactant by forming a bond between the $\alpha$ carbon of one partner and the carbonyl carbon of the second partner. The product is a $\beta$-hydroxy aldehyde or ketone, meaning that the two oxygen atoms in the product have a 1,3 relationship.


Solution -


Solution -

PROBLEM Using curved arrows to indicate the electron flow in each step, show how the base-catalyzed
23-2 reverse-aldol reaction of 4-hydroxy-4-methyl-2-pentanone takes place to yield 2 equivalents of acetone.


Solution - 23.2 Carbonyl Condensations versus Alpha Substitutions

Two of the four general carbonyl-group reactions-carbonyl condensations and $\alpha$ substitutions-take place under basic conditions and involve enolate-ion intermediates. Because the experimental conditions for the two reactions are similar, how can we predict which will occur in a given case? When we generate an enolate ion
with the intention of carrying out an $\alpha$ alkylation, how can we be sure that a carbonyl condensation reaction won't occur instead?

There is no simple answer to this question, but the exact experimental conditions usually have much to do with the result. Alpha-substitution reactions require a full equivalent of strong base and are normally carried out so that the carbonyl compound is rapidly and completely converted into its enolate ion at a low temperature. An electrophile is then added rapidly to ensure that the reactive enolate ion is quenched quickly. In a ketone alkylation reaction, for instance, we might use 1 equivalent of lithium diisopropylamide (LDA) in tetrahydrofuran solution at $-78^{\circ} \mathrm{C}$. Rapid and complete generation of the ketone enolate ion would occur, and no unreacted ketone would remain, meaning that no condensation reaction could take place. We would then immediately add an alkyl halide to complete the alkylation reaction.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0817.jpg?height=226&width=953&top_left_y=668&top_left_x=586)


On the other hand, carbonyl condensation reactions require only a catalytic amount of a relatively weak base, rather than a full equivalent, so that a small amount of enolate ion is generated in the presence of unreacted carbonyl compound. Once a condensation occurs, the basic catalyst is regenerated. To carry out an aldol reaction on propanal, for instance, we might dissolve the aldehyde in methanol, add 0.05 equivalent of sodium methoxide, and then warm the mixture to give the aldol product.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0817.jpg?height=652&width=1267&top_left_y=1127&top_left_x=429)


Solution - 23.3 Dehydration of Aldol Products: Synthesis of Enones

When heated under either acidic or basic conditions, the $\beta$-hydroxy aldehydes or ketones formed in aldol reactions can be dehydrated to yield $\alpha, \beta$-unsaturated products, or conjugated enones (ene + ketone). In fact, it's this loss of water that gives the carbonyl condensation reaction its name, because water condenses out when an enone product forms.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0817.jpg?height=166&width=353&top_left_y=2042&top_left_x=707)


A conjugated enone


Most alcohols are resistant to dehydration by base (Section 17.6) because hydroxide ion is a poor leaving group, but aldol products dehydrate easily because of their carbonyl group. Under basic conditions, an acidic $\alpha$ hydrogen is removed, yielding an enolate ion that expels the nearby ${ }^{-} \mathrm{OH}$ leaving group in an E1cB reaction (Section 11.10). Under acidic conditions, an enol is formed, the -OH group is protonated, and water is expelled in an E1 or E2 reaction.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0818.jpg?height=530&width=1340&top_left_y=185&top_left_x=390)


The reaction conditions needed for aldol dehydration are often only a bit more vigorous (slightly higher temperature, for instance) than the conditions needed for the aldol formation itself. As a result, conjugated enones are usually obtained directly from aldol reactions without isolating the intermediate $\beta$-hydroxy carbonyl compounds.


Conjugated enones are more stable than nonconjugated enones for the same reason that conjugated dienes are more stable than nonconjugated dienes (Section 14.1). Interaction between the $\pi$ electrons of the $\mathrm{C}=\mathrm{C}$ bond and the $\pi$ electrons of the $\mathrm{C}=\mathrm{O}$ group leads to a molecular-orbital description for a conjugated enone with an interaction of the $\pi$ electrons over all four atomic centers (FIGURE 23.3).
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0818.jpg?height=245&width=402&top_left_y=1157&top_left_x=604)
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Propenal
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0818.jpg?height=240&width=413&top_left_y=1154&top_left_x=1086)
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FIGURE 23.3 The $\boldsymbol{\pi}$ bonding molecular orbitals of a conjugated enone (propenal) and a conjugated diene (1,3-butadiene) are similar in shape and are spread over the entire $\pi$ system.


The real value of aldol dehydration is that removal of water from the reaction mixture can be used to drive the aldol equilibrium toward the product. Even though the initial aldol step itself may be unfavorable, as it usually is for ketones, the subsequent dehydration step nevertheless allows many aldol condensations to be carried out in good yield. Cyclohexanone, for example, gives cyclohexylidenecyclohexanone in $92 \%$ yield, even though the initial equilibrium is unfavorable.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0818.jpg?height=278&width=1207&top_left_y=2005&top_left_x=459)


Cyclohexanone
Cyclohexylidenecyclohexanone
(92\%)


WORKED EXAMPLE 23.2 -


What is the structure of the enone obtained from aldol condensation of acetaldehyde?


Strategy -

In the aldol reaction, $\mathrm{H}_{2} \mathrm{O}$ is eliminated and a double bond is formed by removing two hydrogens from the acidic $\alpha$ position of one partner and the carbonyl oxygen from the second partner. The product is thus an $\alpha, \beta$-unsaturated aldehyde or ketone.


Solution -

PROBLEM Aldol condensation of 3-methylcyclohexanone leads to a mixture of two enone products, not 23-4 counting double-bond isomers. Draw them.


Solution - 23.4 Using Aldol Reactions in Synthesis

The aldol reaction yields either a $\beta$-hydroxy aldehyde/ketone or an $\alpha, \beta$-unsaturated aldehyde/ketone, depending on the experimental conditions. By learning how to work backward, it's possible to predict when the aldol reaction might be useful in synthesis. Whenever the target molecule contains either a $\beta$-hydroxy aldehyde/ ketone or a conjugated enone functional group, it might come from an aldol reaction.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0819.jpg?height=229&width=1045&top_left_y=1672&top_left_x=540)


We can extend this kind of reasoning even further by imagining that subsequent transformations might be carried out on the aldol products. For example, a saturated ketone might be prepared by catalytic hydrogenation of the enone product. A good example can be found in the industrial preparation of 2-ethyl-1-hexanol, an alcohol used in the synthesis of plasticizers for polymers. Although 2-ethyl-1-hexanol bears little resemblance to an aldol product at first glance, it is in fact prepared commercially from butanal by an aldol reaction. Working backward, we can reason that 2 -ethyl-1-hexanol might come from 2 -ethylhexanal by a reduction. 2-Ethylhexanal, in turn, might be prepared by catalytic reduction of 2 -ethyl-2-hexenal, which is the aldol condensation product of butanal. The reactions that follow show the sequence in reverse order.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0820.jpg?height=335&width=998&top_left_y=185&top_left_x=558)
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0820.jpg?height=112&width=367&top_left_y=535&top_left_x=825)


PROBLEM Which of the following compounds are aldol condensation products? What is the aldehyde or ketone 23-5 precursor of each?
(a) 2-Hydroxy-2-methylpentanal
(b) 5-Ethyl-4-methyl-4-hepten-3-one


PROBLEM 1-Butanol is prepared commercially by a route that begins with an aldol reaction. Show the steps 23-6 that are likely to be involved.


PROBLEM Show how you would synthesize the following compound using an aldol reaction:
23-7
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0820.jpg?height=359&width=500&top_left_y=1078&top_left_x=417)


Solution - 23.5 Mixed Aldol Reactions

Until now, we've considered only symmetrical aldol reactions, in which the two carbonyl components have been the same. What would happen, though, if an aldol reaction were carried out between two different carbonyl partners?


Solution - 23.5 Mixed Aldol Reactions

In general, a mixed aldol reaction between two similar aldehyde or ketone partners leads to a mixture of four possible products. For example, base treatment of a mixture of acetaldehyde and propanal gives a complex product mixture containing two "symmetrical" aldol products and two "mixed" aldol products. Clearly, such a reaction is of no practical value.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0820.jpg?height=468&width=1134&top_left_y=1872&top_left_x=493)


Solution - 23.5 Mixed Aldol Reactions

On the other hand, mixed aldol reactions can lead cleanly to a single product if either of two conditions is met:


Solution - 23.5 Mixed Aldol Reactions

- If one of the carbonyl partners contains no $\alpha$ hydrogens (and thus can't form an enolate ion to become a donor), but does contain an unhindered carbonyl group (and so is a good acceptor of nucleophiles), then a mixed aldol reaction is likely to be successful. This is the case, for instance, when either benzaldehyde or
formaldehyde is used as one of the carbonyl partners.
Neither benzaldehyde nor formaldehyde can form an enolate ion to add to another partner, yet both compounds have an unhindered carbonyl group. The ketone 2-methylcyclohexanone, for instance, gives the mixed aldol product on reaction with benzaldehyde.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0821.jpg?height=299&width=1286&top_left_y=409&top_left_x=428)
- If one of the carbonyl partners is much more acidic than the other, and is thus transformed into its enolate ion in preference to the other, then a mixed aldol reaction is likely to be successful. Ethyl acetoacetate, for instance, is completely converted into its enolate ion in preference to enolate ion formation from monocarbonyl partners. Thus, aldol condensations of monoketones with ethyl acetoacetate occur preferentially to give the mixed product.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0821.jpg?height=326&width=1275&top_left_y=943&top_left_x=428)

The situation can be summarized by saying that a mixed aldol reaction leads to a mixture of products unless one of the partners either has no $\alpha$ hydrogens but is a good electrophilic acceptor (such as benzaldehyde) or is an unusually acidic nucleophilic donor (such as ethyl acetoacetate).


Solution - 23.5 Mixed Aldol Reactions


Solution - 23.6 Intramolecular Aldol Reactions

The aldol reactions we've seen thus far have all been intermolecular, meaning that they have taken place between two different molecules. When certain dicarbonyl compounds are treated with base, however, an intramolecular aldol reaction can occur, leading to the formation of a cyclic product. For example, base treatment of a 1,4-diketone such as 2,5-hexanedione yields a cyclopentenone product, and base treatment of a 1,5-diketone such as 2,6-heptanedione yields a cyclohexenone.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0822.jpg?height=240&width=674&top_left_y=189&top_left_x=731)


$$
\begin{aligned}
& \text { 2,5-Hexanedione } \\
& \text { (a 1,4-diketone) }
\end{aligned}
$$


2,6-Heptanedione (a 1,5-diketone) -


2,6-Heptanedione (a 1,5-diketone) -

The mechanism of intramolecular aldol reactions is similar to that of intermolecular reactions. The only difference is that both the nucleophilic carbonyl anion donor and the electrophilic carbonyl acceptor are now in the same molecule. One complication, however, is that intramolecular aldol reactions might lead to a mixture of products, depending on which enolate ion is formed. For example, 2,5-hexanedione might yield either the five-membered-ring product 3-methyl-2-cyclopentenone or the three-membered-ring product (2-methylcyclopropenyl) ethanone (FIGURE 23.4). In practice, though, only the cyclopentenone is formed.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0822.jpg?height=709&width=1166&top_left_y=1147&top_left_x=474)


2,6-Heptanedione (a 1,5-diketone) -

FIGURE 23.4 Intramolecular aldol reaction of 2,5-hexanedione yields 3-methyl-2-cyclopentenone rather than the alternative cyclopropene.


2,6-Heptanedione (a 1,5-diketone) -

The selectivity observed in the intramolecular aldol reaction of 2,5-hexanedione is due to the fact that all steps in the mechanism are reversible, so an equilibrium is reached. Thus, the relatively strain-free cyclopentenone product is considerably more stable than the highly strained cyclopropene alternative. For similar reasons, intramolecular aldol reactions of 1,5-diketones lead only to cyclohexenone products rather than to the more strained acylcyclobutenes.


2,6-Heptanedione (a 1,5-diketone) -

PROBLEM Treatment of a 1,3-diketone such as 2,4-pentanedione with base does not give an aldol
23-9 condensation product. Explain.
PROBLEM What product would you expect to obtain from base treatment of 1,6-cyclodecanedione? 23-10
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0823.jpg?height=212&width=399&top_left_y=192&top_left_x=462)


2,6-Heptanedione (a 1,5-diketone) - 23.7 The Claisen Condensation Reaction

Esters, like aldehydes and ketones, are weakly acidic. When an ester with an $\alpha$ hydrogen is treated with 1 equivalent of a base such as sodium ethoxide, a reversible carbonyl condensation reaction occurs to yield a $\beta$-keto ester. For instance, ethyl acetate yields ethyl acetoacetate on base treatment. This reaction between two ester molecules is known as the Claisen condensation reaction. (We'll use ethyl esters, abbreviated "Et," for consistency, but other esters will also work.)
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0823.jpg?height=269&width=1339&top_left_y=798&top_left_x=393)


The mechanism of the Claisen condensation is similar to that of the aldol condensation and involves the nucleophilic addition of an ester enolate ion to the carbonyl group of a second ester molecule (FIGURE 23.5). The only difference between the aldol condensation of an aldehyde or ketone and the Claisen condensation of an ester involves the fate of the initially formed tetrahedral intermediate. The tetrahedral intermediate in the aldol reaction is protonated to give an alcohol product-exactly the behavior previously seen for aldehydes and ketones (Section 19.4). The tetrahedral intermediate in the Claisen reaction, however, expels an alkoxide leaving group to yield an acyl substitution product-as previously seen for esters (Section 21.6).


FIGURE 23.5 MECHANISM -


FIGURE 23.5 MECHANISM -

If the starting ester has more than one acidic $\alpha$ hydrogen, the product $\beta$-keto ester has a highly acidic, doubly activated hydrogen atom that can be abstracted by base. This deprotonation of the product requires the use of a full equivalent of base rather than a catalytic amount. Furthermore, the deprotonation serves to drive the equilibrium completely to the product side so that high yields are usually obtained in Claisen condensations.


WORKED EXAMPLE 23.3 -


Predicting the Product of a Claisen Condensation Reaction -

What product would you obtain from Claisen condensation of ethyl propanoate?


Strategy -

The Claisen condensation of an ester results in loss of one molecule of alcohol and formation of a product in which an acyl group of one reactant bonds to the $\alpha$ carbon of the second reactant. The product is a $\beta$-keto ester.


Strategy -

Solution
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0825.jpg?height=221&width=1156&top_left_y=659&top_left_x=482)


Strategy -

PROBLEM Show the products you would expect to obtain by Claisen condensation of the following esters:
23-11
(a) $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCH}_{2} \mathrm{CO}_{2} \mathrm{Et}$
(b) Ethyl phenylacetate
(c) Ethyl cyclohexylacetate


Strategy -

PROBLEM As shown in Figure 23.5, the Claisen reaction is reversible. That is, a $\beta$-keto ester can be cleaved 23-12 by base into two fragments. Using curved arrows to indicate electron flow, show the mechanism by which this cleavage occurs.
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Strategy - 23.8 Mixed Claisen Condensations

The mixed Claisen condensation of two different esters is similar to the mixed aldol condensation of two different aldehydes or ketones (Section 23.5). Mixed Claisen reactions are successful only when one of the two ester components has no $\alpha$ hydrogens and thus can't form an enolate ion. For example, ethyl benzoate and ethyl formate can't form enolate ions and thus can't serve as donors. They can, however, act as the electrophilic acceptor components in reactions with other ester anions to give mixed $\beta$-keto ester products.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0825.jpg?height=299&width=1266&top_left_y=1707&top_left_x=424)

Mixed Claisen-like reactions can also be carried out between an ester and a ketone, resulting in the synthesis of a $\beta$-diketone. The reaction works best when the ester component has no $\alpha$ hydrogens and thus can't act as the nucleophilic donor. For example, ethyl formate gives high yields in mixed Claisen condensations with ketones.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0825.jpg?height=196&width=282&top_left_y=2152&top_left_x=496)


2,2-Dimethylcyclohexanone (donor) -


2,2-Dimethylcyclohexanone (donor) -

A $\boldsymbol{b}$-keto aldehyde (91\%)


WORKED EXAMPLE 23.4 -


Predicting the Product of a Mixed Claisen Condensation Reaction -

Diethyl oxalate, $\left(\mathrm{CO}_{2} \mathrm{Et}\right)_{2}$, often gives high yields in mixed Claisen reactions. What product would you expect to obtain from a mixed Claisen reaction of ethyl acetate with diethyl oxalate?


Strategy -

A mixed Claisen reaction is effective when only one of the two partners has an acidic $\alpha$ hydrogen atom. In the present case, ethyl acetate can be converted into its enolate ion, but diethyl oxalate cannot. Thus, ethyl acetate acts as the donor and diethyl oxalate as the acceptor.


Strategy -

Solution
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0826.jpg?height=318&width=1131&top_left_y=746&top_left_x=494)


Strategy -

PROBLEM What product would you expect from the following mixed Claisen-like reaction?
23-13
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0826.jpg?height=351&width=1255&top_left_y=1174&top_left_x=435)


Strategy - 23.9 Intramolecular Claisen Condensations: The Dieckmann Cyclization

Intramolecular Claisen condensations can be carried out with diesters, just as intramolecular aldol condensations can be carried out with diketones (Section 23.6). Called the Dieckmann cyclization, this reaction works best on 1,6-diesters and 1,7-diesters. Intramolecular Claisen cyclization of a 1,6-diester gives a five-membered cyclic $\beta$-keto ester, and cyclization of a 1,7-diester gives a six-membered cyclic $\beta$-keto ester.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0826.jpg?height=695&width=1039&top_left_y=1821&top_left_x=543)

The mechanism of the Dieckmann cyclization, shown in FIGURE 23.6, is the same as that of the Claisen condensation. One of the two ester groups is converted into an enolate ion, which carries out a nucleophilic acyl substitution on the second ester group at the other end of the molecule. A cyclic $\beta$-keto ester product results.

FIGURE 23.6 MECHANISM
Mechanism of the Dieckmann cyclization of a 1,7-diester to yield a cyclic $\beta$-keto ester product.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=198&width=270&top_left_y=584&top_left_x=1139)
(1) Base abstracts an acidic $\alpha$ proton from
the carbon atom next to one of the ester groups, yielding an enolate ion.
(1) $\downarrow \mathrm{Na}^{+- \text {OEt }}$
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=246&width=456&top_left_y=907&top_left_x=1130)


O |
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=196&width=242&top_left_y=1257&top_left_x=1142)
(3) $\downarrow$
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=177&width=389&top_left_y=1581&top_left_x=1150)
(4) Deprotonation of the acidic $\beta$-keto ester gives an enolate ion...
-
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=198&width=454&top_left_y=1885&top_left_x=1128)
(5) $\downarrow \mathrm{H}_{3} \mathrm{O}^{+}$
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0827.jpg?height=175&width=377&top_left_y=2211&top_left_x=1156)


The cyclic $\beta$-keto ester produced in a Dieckmann cyclization can be further alkylated and decarboxylated by a series of reactions analogous to those used in the acetoacetic ester synthesis (Section 22.7). Alkylation and
subsequent decarboxylation of ethyl 2-oxocyclohexanecarboxylate, for instance, yields a 2-alkylcyclohexanone. The overall sequence of (1) Dieckmann cyclization, (2) $\beta$-keto ester alkylation, and (3) decarboxylation is a powerful method for preparing 2 -substituted cyclopentanones and cyclohexanones.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0828.jpg?height=358&width=1381&top_left_y=355&top_left_x=364)


PROBLEM What product would you expect from the following reaction?
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0828.jpg?height=138&width=801&top_left_y=752&top_left_x=307)


PROBLEM Dieckmann cyclization of diethyl 3-methylheptanedioate gives a mixture of two $\beta$-keto ester
23-15 products. What are their structures, and why is a mixture formed?


Strategy - 23.10 Conjugate Carbonyl Additions: The Michael Reaction

We saw in Section 19.13 that certain nucleophiles, such as amines, react with $\alpha, \beta$-unsaturated aldehydes and ketones to give a conjugate addition product, rather than a direct addition product.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0828.jpg?height=288&width=1099&top_left_y=1192&top_left_x=513)


Exactly the same kind of conjugate addition can occur when a nucleophilic enolate ion reacts with an $\alpha, \beta$-unsaturated carbonyl compound-a process known as the Michael reaction after Arthur Michael at Tufts College and Harvard University.


The best Michael reactions are those that take place when a particularly stable enolate ion, such as that derived from a $\beta$-keto ester or other 1,3-dicarbonyl compound, adds to an unhindered $\alpha, \beta$-unsaturated ketone. For example, ethyl acetoacetate reacts with 3-buten-2-one in the presence of sodium ethoxide to yield the conjugate addition product.
![](https://cdn.mathpix.com/cropped/2025_02_06_5556f7656cbdcaa0f9a7g-0828.jpg?height=194&width=1275&top_left_y=1822&top_left_x=420)


Ethyl
3-Buten-2-one


acetoacetate -

Michael reactions take place by addition of a nucleophilic enolate ion donor to the $\beta$ carbon of an $\alpha, \beta$-unsaturated carbonyl acceptor, according to the mechanism shown in FIGURE 23.7.


FIGURE 23.7 MECHANISM -

Mechanism of the Michael reaction between a $\boldsymbol{\beta}$-keto ester and an
$\boldsymbol{\alpha}, \boldsymbol{\beta}$-unsaturated ketone. The reaction is a conjugate addition of an enolate ion to
the unsaturated carbonyl compound.


FIGURE 23.7 MECHANISM -

The base catalyst removes an acidic alpha proton from the starting $\beta$-keto ester to generate a stabilized enolate ion nucleophile.