Concept explainers
a)
Interpretation:
The dehydration product formed in the addition reaction of butanal along with the mechanism of its formation is to be predicted.
Concept introduction:
The β- hydroxyl aldehyde or ketone obtained loses a molecule of water upon heating to give an α, β- unsaturated aldehyde or ketone.
To predict:
The dehydration product formed in the addition reaction of butanal along with the mechanism of its formation.
Answer to Problem 28MP
The dehydration product formed in the addition reaction of butanal is 2-ethyl-2-hexenal.
The mechanism of its formation is
Explanation of Solution
In the first step the base picks up an acidic proton from the diketone to produce the enolate anion. In the next step the nucleophilic enolate anion attacks the electrophilic carbon of the other carbonyl group in the same molecule to give an alkoxide. In the next step the alkoxide intermediate is protonated to yield the β- hydroxyl aldehyde. Removal of a proton by the base from the hydroxy aldehyde leads to the formation of α, β- unsaturated aldehyde.
The dehydration product formed in the addition reaction of butanal is 2-ethyl-2-hexenal.
The mechanism of its formation is
b)
Interpretation:
The dehydration product formed in the addition reaction given along with the mechanism of its formation is to be predicted.
Concept introduction:
Aldehydes and ketones that have α- hydrogen atom undergo aldol condensation to yield a β- hydroxyl aldehyde or ketone as the product. The reaction occurs in three steps i) Abstraction of α- hydrogen by a base to yield an enolate anion ii) Attack of the anion on the carbonyl carbon of another molecule iii) Protonation of the alkoxide intermediate.
The β- hydroxyl aldehyde or ketone obtained on heating loses a water molecule to yield an α, β- unsaturated aldehyde or ketone.
To identify:
The dehydration product formed in the addition reaction of cyclobutanone along with the mechanism of its formation.
Answer to Problem 28MP
The dehydration product formed in the addition reaction of cyclobutanone is
The mechanism of its formation is
Explanation of Solution
In the first step the base picks up a proton from the α-carbon of one cyclobutanone molecule to produce the enolate anion. In the next step the nucleophilic enolate anion attacks the electrophilic carbonyl carbon of another cyclobutanoe molecule to give an alkoxide. In the next step the alkoxide intermediate is protonated to yield a β- hydroxyketone. In the final step the base picks up a proton from the hydroxyl group that leads to the formation of α, β- unsaturated ketone.
The dehydration product formed in the addition reaction of cyclobutanone is
The mechanism of its formation is
c)
Interpretation:
The dehydration product formed in the addition reaction given along with the mechanism of its formation is to be predicted.
Concept introduction:
The reaction given is a mixed aldol reaction. Aldehydes and ketones that have α- hydrogen atom undergo aldol condensation to yield a β- hydroxyl aldehyde or ketone as the product. The reaction occurs in three steps i) Abstraction of α- hydrogen by a base to yield an enolate anion ii) Attack of the anion on the carbonyl carbon of another molecule iii) Protonation of the alkoxide intermediate.
The β- hydroxyl aldehyde or ketone loses a molecule of water when heated in the presence of a base to yield α, β- unsaturated aldehyde or ketone.
To identify:
The dehydration product formed in the addition reaction given along with the mechanism of its formation.
Answer to Problem 28MP
The dehydration product formed in the addition reaction given is
The mechanism of its formation is
Explanation of Solution
In the first step the base picks up a proton from the α-carbon of acetaldehyde as it has α- hydrogen atoms to produce the enolate anion. In the next step the nucleophilic enolate anion attacks the electrophilic carbonyl carbon of benzaldehyde to give an alkoxide. In the next step the alkoxide intermediate is protonated to yield a β- hydroxyaldehyde. In the final step the base picks up a proton from the hydroxyl group that leads to the formation of α, β- unsaturated aldehyde.
The dehydration product formed in the addition reaction given is
The mechanism of its formation is
d)
Interpretation:
The product formed in the addition reaction given along with the mechanism of its formation is to be predicted.
Concept introduction:
In intramolecular aldol reactions dicarbonyl compounds such as diketones react with a base to yield a cyclic enone as the products. The reaction occurs in four steps i) Abstraction of α-hydrogen by a base to yield an enolate anion ii) Attack of the anion on the carbonyl carbon in another molecule iii) Protonation of the alkoxide intermediate. iv) Loss of water from the keto alcohol upon heating.
To identify:
The product formed in the addition reaction given along with the mechanism of its formation.
Answer to Problem 28MP
The product formed in the addition reaction given is
The mechanism of its formation is
Explanation of Solution
In the first step the base picks up an acidic proton from the diketone to produce the enolate anion. In the next step the nucleophilic enolate anion attacks the electrophilic carbon of the other carbonyl group in the same molecule to give an alkoxide. In the next step the alkoxide intermediate is protonated to yield a hydroxyl ketone. In the final step the base picks up a proton from the hydroxyl group that leads to the formation of α, β- unsaturated aldehyde.
The product formed in the addition reaction given is
The mechanism of its formation is
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Chapter 23 Solutions
Bundle: Organic Chemistry, 9th, Loose-Leaf + OWLv2, 4 terms (24 months) Printed Access Card
- 4. Read paragraph 4.15 from your textbook, use your calculated lattice energy values for CuO, CuCO3 and Cu(OH)2 an explain thermal decomposition reaction of malachite: Cu2CO3(OH)2 →2CuO + H2O + CO2 (3 points)arrow_forwardPlease sirrr soollveee these parts pleaseeee and thank youuuuuarrow_forwardIII O Organic Chemistry Using wedges and dashes in skeletal structures Draw a skeletal ("line") structure for each of the molecules below. Be sure your structures show the important difference between the molecules. key O O O O O CHON Cl jiii iiiiiiii You can drag the slider to rotate the molecules. Explanation Check Click and drag to start drawing a structure. Q Search X G ©2025 McGraw Hill LLC. All Rights Reserved. Terms of Use F 3 W C 3/5arrow_forward
- 3. Use Kapustinskii's equation and data from Table 4.10 in your textbook to calculate lattice energies of Cu(OH)2 and CuCO3 (4 points)arrow_forward2. Copper (II) oxide crystalizes in monoclinic unit cell (included below; blue spheres 2+ represent Cu²+, red - O²-). Use Kapustinski's equation (4.5) to calculate lattice energy for CuO. You will need some data from Resource section of your textbook (p.901). (4 points) CuOarrow_forwardWhat is the IUPAC name of the following compound? OH (2S, 4R)-4-chloropentan-2-ol O (2R, 4R)-4-chloropentan-2-ol O (2R, 4S)-4-chloropentan-2-ol O(2S, 4S)-4-chloropentan-2-olarrow_forward
- Use the reaction coordinate diagram to answer the below questions. Type your answers into the answer box for each question. (Watch your spelling) Energy A B C D Reaction coordinate E A) Is the reaction step going from D to F endothermic or exothermic? A F G B) Does point D represent a reactant, product, intermediate or transition state? A/ C) Which step (step 1 or step 2) is the rate determining step? Aarrow_forward1. Using radii from Resource section 1 (p.901) and Born-Lande equation, calculate the lattice energy for PbS, which crystallizes in the NaCl structure. Then, use the Born-Haber cycle to obtain the value of lattice energy for PbS. You will need the following data following data: AH Pb(g) = 196 kJ/mol; AHƒ PbS = −98 kJ/mol; electron affinities for S(g)→S¯(g) is -201 kJ/mol; S¯(g) (g) is 640kJ/mol. Ionization energies for Pb are listed in Resource section 2, p.903. Remember that enthalpies of formation are calculated beginning with the elements in their standard states (S8 for sulfur). The formation of S2, AHF: S2 (g) = 535 kJ/mol. Compare the two values, and explain the difference. (8 points)arrow_forwardIn the answer box, type the number of maximum stereoisomers possible for the following compound. A H H COH OH = H C Br H.C OH CHarrow_forward
