Early chemists could envision three possible mechanisms

Write a structure for each of the following: a. N , N -dimethylhexanamide b. 3,3-dimethylhexanamide c. cyclohexanecarbonyl chloride d. propanenitrile e. propionamide f. sodium acetate g. benzoic anhydride h. b -valerolactone i. 3-methylbutanenitrile j. cycloheptanecarboxylic acid k. benzoyl chlorid

Name the following compounds:

What products would be formed from the reaction of benzoyl chloride with the following reagents? a. sodium acetate b. water c. excess dimethylamine d. aqueous HCl e. aqueous NaOH f. cyclohexanol g. excess benzylamine h. 4-chlorophenol

What products would be obtained from the following hydrolysis reactions?

a. List the following esters in order of decreasing reactivity in the i rst slow step of a nucleophilic addition-elimination reaction (formation of the tetrahedral intermediate): Cl AB C O CH3 O C O CH3 O C O CH3 O C b. List the same esters in order of decreasing reactivity in the second slow step of a nucleophilic additionelimination reaction (collapse of the tetrahedral intermediate).

Because bromocyclohexane is a secondary alkyl halide, both cyclohexanol and cyclohexene are formed when the alkyl halide reacts with hydroxide ion. Suggest a method to synthesize cyclohexanol from bromocyclohexane that would form little or no cyclohexene.

a. Which compound would you expect to have a higher dipole moment, methyl acetate or butanone? b. Which would you expect to have a higher boiling point?

How could you use 1 H NMR spectroscopy to distinguish among the following esters?

If propionyl chloride is added to one equivalent of methylamine, only a 50% yield of N -methylpropanamide is obtained. If, however, the acyl chloride is added to two equivalents of methylamine, the yield of N -methylpropanamide is almost 100%. Explain these observations.

a. When a carboxylic acid is dissolved in isotopically labeled water (H 2 18 O) and an acid catalyst is added, the label is incorporated into both oxygens of the acid. Propose a mechanism to account for this.

List the following compounds in order of decreasing frequency of the carbonoxygen double-bond stretch:

Using an alcohol for one method and an alkyl halide for the other, show two ways to make each of the following esters: a. propyl acetate (odor of pears) b. isopentyl acetate (odor of bananas) c. ethyl butyrate (odor of pineapple) d. methyl phenylethanoate (odor of honey)

What reagents would you use to convert methyl propanoate into the following compounds? a. isopropyl propanoate b. sodium propanoate c. N -ethylpropanamide d. propanoic acid

What products would you expect to obtain from the following reactions? a. malonic acid + 2 acetyl chloride b. methyl carbamate + methylamine c. urea + water d. b@ethylglutaric acid + acetyl chloride +

A compound with molecular formula C 5 H 10 O 2 gives the following IR spectrum. When it undergoes acid-catalyzed hydrolysis, the compound with the 1 H NMR spectrum shown here is formed. Identify the compounds.

Aspartame, the sweetener used in the commercial products NutraSweet and Equal, is 200 times sweeter than sucrose. What products would be obtained if aspartame were hydrolyzed completely in an aqueous solution of HCl?

Which of the following reactions will not give the carbonyl product shown?

1,4-Diazabicyclo[2.2.2]octane (abbreviated DABCO) is a tertiary amine that catalyzes transesterii cation reactions. Propose a mechanism to show how it does this.

Two products, A and B, are obtained from the reaction of 1-bromobutane with NH 3 . Compound A reacts with acetyl chloride to form C, and compound B reacts with acetyl chloride to form D. The IR spectra of C and D are shown. Identify A, B, C, and D.

Phosgene (\(COCl_{2}\)) was used as a poison gas in World War I. Give the product that would be formed from the reaction of phosgene with each of the following reagents: a. one equivalent of methanol b. excess methanol c. excess propylamine d. excess water

What reagent should be used to carry out the following reaction?

When a student treated butanedioic acid with thionyl chloride, she was surprised to i nd that the product she obtained was an anhydride rather than an acyl chloride. Propose a mechanism to explain why she obtained an anhydride.

What are the products of the following reactions?

When treated with an equivalent of methanol, compound A, with molecular formula C 4 H 6 Cl 2 O, forms the compound whose 1 H NMR spectrum is shown here. Identify compound A.

a. Identify the two products obtained from the following reaction: b. A student carried out the preceding reaction, but stopped it before it was half over, whereupon he isolated the major product. He was surprised to find that the product he isolated was neither of the products obtained when the reaction was allowed to go to completion. What product did he isolate?

An aqueous solution of a primary or secondary amine reacts with an acyl chloride to form an amide as the major product. However, if the amine is tertiary, an amide is not formed. What product is formed? Explain.

Identify the major and minor products of the following reaction:

a. A student did not obtain any ester when he added 2,4,6-trimethylbenzoic acid to an acidic solution of methanol. Why? ( Hint: Build models.) b. Would he have encountered the same problem if he had tried to synthesize the methyl ester of 4 -methylbenzoic acid in the same way?

When a compound with molecular formula C 11 H 14 O 2 undergoes acid-catalyzed hydrolysis, one of the products that is isolated gives the following 1 H NMR spectrum. Identify the compound.

Cardura, a drug used to treat hypertension, is synthesized as shown here. Br Br OH OH A B O O + + CH3OH K2CO3 KOH HCl H2O O O O O Cardura O OCH3 C OCH3 C OH C a. Identify the intermediate (A) and show the mechanism for its formation. b. Show the mechanism for conversion of A to B. Which would be formed more rapidly, A or B?

a. If the equilibrium constant for the reaction of acetic acid and ethanol to form ethyl acetate is 4.02, what will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with equal amounts of acetic acid and ethanol? b. What will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with 10 times more ethanol than acetic acid? Hint: Recall the quadratic equation: for ax 2 + bx + c = 0 , x = -b { 1b 2 - 4ac2 1>2 2a c. What will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with 100 times more ethanol than acetic acid?

The 1 H NMR spectra for two esters with molecular formula C 8 H 8 O 2 are shown next. If each of the esters is added to an aqueous solution with a pH of 10, which of the esters will be hydrolyzed more rapidly?

Show how the following compounds could be prepared from the given starting materials. You can use any necessary organic or inorganic reagents.

Is the acid-catalyzed hydrolysis of acetamide a reversible or an irreversible reaction? Explain.

What product would you expect to obtain from each of the following reactions?

The reaction of a nitrile with an alcohol in the presence of a strong acid forms an N-substituted amide. This reaction, known as the Ritter reaction , does not work with primary alcohols. RC N R + OH C O HCl the Ritter reaction R NHR a. Propose a mechanism for the Ritter reaction. b. Why does the Ritter reaction not work with primary alcohols? c. How does the Ritter reaction differ from the acid-catalyzed hydrolysis of a nitrile to form an amide?

The intermediate shown here is formed during the hydroxide-ion-promoted hydrolysis of the ester group. Propose a mechanism for the reaction.

The following compound has been found to be an inhibitor of penicillinase. The enzyme can be reactivated by hydroxylamine (NH 2 OH). Propose a mechanism to account for the inhibition and for the reactivation.

Propose a mechanism that will account for the formation of the product.

Catalytic antibodies catalyze a reaction by forcing the conformation of the substrate in the direction of the transition state. The synthesis of the antibody is carried out in the presence of a transition state analoga stable molecule that structurally resembles the transition state. This causes an antibody to be generated that will recognize and bind to the transition state, thereby stabilizing it. For example, the following transition state analog has been used to generate a catalytic antibody that catalyzes the hydrolysis of the structurally similar ester: O O O HO NO2 transition state analog P O O HO NO2 O O OH + HO HO NO2 O O H2O a. Draw the transition state for the hydrolysis reaction. b. The following transition state analog is used to generate a catalytic antibody for the catalysis of ester hydrolysis. Draw the structure of an ester whose rate of hydrolysis would be increased by this catalytic antibody. O O O N + NO2 P c. Design a transition state analog that would catalyze amide hydrolysis at the amide group indicated.

Information about the mechanism of the reaction undergone by a series of substituted benzenes can be obtained by plotting the logarithm of the observed rate constant determined at a particular pH against the Hammett substituent constant ( s ) for the particular substituent. The s value for hydrogen is 0. Electron-donating substituents have negative s values; the more strongly electron donating the substituent, the more negative its s value will be. Electron-withdrawing substituents have positive s values; the more strongly electron withdrawing the substituent, the more positive its s value will be. The slope of a plot of the logarithm of the rate constant versus s is called the r (rho) value. The r value for the hydroxide-ion-promoted hydrolysis of a series of meta- and para-substituted ethyl benzoates is +2.46 ; the r value for amide formation for the reaction of a series of meta- and para-substituted anilines with benzoyl chloride is -2.78 . Y OCH2CH3 Y Y ortho-substituted meta-substituted para- substituted C O OCH2CH3 C O OCH2CH3 C O a. Why does one set of experiments give a positive r value, whereas the other set of experiments gives a negative r value? b. Why were ortho-substituted compounds not included in the experiment? c. What would you predict the sign of the r value to be for the ionization of a series of meta- and para-substituted benzoic acids?

The aromas of many flowers and fruits are due to esters such as those shown in this problem. What are the common names of these esters? (Also see Problem \(66\) .) Equation Transcription: Text Transcription: 66

Problem 2P The word “lactone” has its origin in lactic acid, a three-carbon carboxylic acid with an OH group on the ?-carbon. Ironically, lactic acid (for its structure, see the structure of lactate near the top of this page) cannot form a lactone. Why not?

Name the following compounds:

Draw the structure of each of the following: a. phenyl acetate e. ethyl 2-chloropentanoate b. \(\gamma\)-caprolactam f. \(\beta\)-bromobutyramide c. N-benzylethanamide g. cyclohexanecarbonyl chloride d. \(\gamma\)-methylcaproic acid h. \(\alpha\)-chlorovaleric acid

Problem 5P Which is a correct statement? A. The delocalization energy of an ester is about 18 kcal/mol, and the delocalization energy of an amide is about 10 kcal/mol. B. The delocalization energy of an ester is about 10 kcal/mol, and the delocalization energy of an amide is about 18 kcal/mol.

Which is longer, the carbon–oxygen single bond in a carboxylic acid or the carbon–oxygen bond in an alcohol? Why?

Problem 7P There are three carbon–oxygen bonds in methyl acetate. a. What are their relative lengths? b. What are the relative infrared (IR) stretching frequencies of these bonds?

Problem 8P Match the compound to the appropriate carbonyl IR absorption band: acyl chloride 1800 cm-1 ester 1640 cm-1 amide 1730 cm-1

Problem 9P Explain the difference in the melting points of the following fatty acids: a. palmitic acid and stearic acid b. palmitic acid and palmitoleic acid

Problem 10P What products are formed when arachidonic acid reacts with excess ozone followed by treatment with dimethyl sulfide? (Hint: See Section 6.11.)

Problem 11P a. The pka of HCl is —7; the pKa of H2O is 15.7. What is the product of the reaction of acetyl chloride with HO?? ________________ b. The pka of NH3 is 36; the pka of H2O is 15.7. What is the product of the reaction of acetamide with HO??

a. Which compound will have the stretching vibration for its carbonyl group at the highest frequency: acetyl chloride, methyl acetate, or acetamide? b. Which one will have the stretching vibration for its carbonyl group at the lowest frequency?

Using the \(p K_{a}\) values listed in Table \(16.1\) , predict the products of the following reactions: Equation Transcription: Text Transcription: pK_a 16.1

Problem 14P Is the following statement true or false? If the newly added group in the tetrahedral intermediate is a stronger base than the group attached to the acyl group in the reactant, then formation of the tetrahedral intermediate is the rate-limiting step of a nucleophilic addition–elimination reaction.

Problem 15P What will be the product of a nucleophilic addition–elimination reaction—a new carboxylic acid derivative, a mixture of two carboxylic acid derivatives, or no reaction—if the new group in the tetrahedral intermediate is the following? a. a stronger base than the substituent that was attached to the acyl group b. a weaker base than the substituent that was attached to the acyl group c. similar in basicity to the substituent that was attached to the acyl group

Starting with acetyl chloride, what neutral nucleophile would you use to make each of the following compounds?

Problem 18P Write the mechanism for each of the following reactions: a. the reaction of acetyl chloride with water to form acetic acid b. the reaction of benzoyl chloride with excess methylamine to form N-methylbenzamide

Problem 19P We have seen that it is necessary to use excess amine in the reaction of an acyl chloride with an amine. Explain why it is not necessary to use excess alcohol in the reaction of an acyl chloride with an alcohol.

Problem 20P Write the mechanism for each of the following reactions: a. the noncatalyzed hydrolysis of methyl propionate b. the aminolysis of phenyl formate, using melhylamine

Problem 21P a. State three factors cause the uncatalyzed hydrolysis of an ester to be a slow reaction. b. Which is faster, the hydrolysis of an ester or the aminolysis of the same ester? Explain your answer.

What products would be formed from the acid-catalyzed hydrolysis of the following esters?

Problem 24P Using the mechanism for the acid-catalyzed hydrolysis of an ester as your guide, write the mechanism—showing all the curved arrows—for the acid-catalyzed reaction of acetic acid and methanol to form methyl acetate. Use HB+ and :B to represent the proton-donating and protonremoving species, respectively.

Problem 25P In the mechanism for the acid-catalyzed hydrolysis of an ester, a. what species could be represented by HB+? b. what species could be represented by :B? c. what species is HB+ most likely to be in the hydrolysis reaction? d. what species is HB+ most likely to be in the reverse reaction?

Problem 27P What products would be obtained from the following reactions? a. ethyl benzoate + excess isopropanol + HCl b. phenyl acetate + excess ethanol + HCl

Problem 28P Write the mechanism for the acid-catalyzed transesterification of ethyl acetate with methanol.

Problem 29P Write the mechanism for the acid-catalyzed reaction of tert-butyl acetate with methanol.

Problem 30P a. What species other than an acid can be used to increase the rate of the transesterification reaction that converts methyl acetate to propyl acetate? b. Explain why the rate of aminolysis of an ester cannot be increased by H+, HO–, or RO–.

Problem 31P When butanoic acid and 18O-labeled methanol react under acidic conditions, what compounds will be labeled when the reaction has reached equilibrium?

D. N. Kursanov, a Russian chemist, proved that the bond that is broken in the hydroxide-ion promoted hydrolysis of an ester is the acyl \(C-O\) bond, rather than the alkyl \(C-O\) bond, by studying the hydrolysis of the following ester under basic conditions: a. What products contained the \({ }^{18} O\) label? b. What product would have contained the \({ }^{18} O\) label if the alkyl \(C-O\) bond had broken? Equation Transcription: Text Transcription: C-O ^18 O

Early chemists could envision three possible mechanisms for hydroxide-ion-promoted ester hydrolysis. Devise an experiment that would show which of the three is the actual mechanism. 1. a nucleophilic addition–elimination reaction 2. an \(S_{N} 2\) reaction 3. an \(S_{N} 1\) reaction Equation Transcription: Text Transcription: S_N 2 S_N 1

Problem 34P An oil obtained from coconuts is unusual in that all three fatty acid components are identi­cal. The molecular formula of the oil is C45H8606. What is the molecular formula of the carboxylate ion obtained when the oil is saponified?

Problem 36P Draw the structure of an optically inactive fat that, when hydrolyzed under acidic conditions, forms glycerol, one equivalent of lauric acid, and two equivalents of stearic acid.

Which has a higher melting point, glyceryl tripalmitoleate or glyceryl tripalmitate? (The structures of the fatty acid constituents of these compounds can be found in Table \(16.2\) .) Equation Transcription: Text Transcription: 16.2

Problem 37P Draw the structure of an optically active fat that, when hydrolyzed under acidic conditions, forms the same products as the fat in Problem 36. 36. Draw the structure of an optically inactive fat that, when hydrolyzed under acidic conditions, forms glycerol, one equivalent of lauric acid, and two equivalents of stearic acid.

Problem 38P Show how each of the following esters could be prepared using a carboxylic acid as one of the starting materials: a. methyl butyrate (odor of apples) b. octyl acetate (odor of oranges)

Propose a mechanism for the following reaction. (Hint: Number the carbons to help you see where they end up in the product.)

Problem 42P Write the mechanism for the acid-catalyzed reaction of an amide with an alcohol to form an ester.

Problem 40P What acyl chloride and what amine would be required to synthesize the following amides? a. N-ethylbutanamide b. N,N-dimethylben/amide

List the following amides in order from greatest reactivity to least reactivity toward acid catalyzed hydrolysis:

What alkyl bromide would you use in a Gabriel synthesis to prepare each of the following amines? a. Pentylamine b. Isohexylamine c. benzylamine d. cyclohexylamine

Primary amines can also be prepared by the reaction of an alkyl halide with azide ion, followed by catalytic hydrogenation. What advantage do this method and the Gabriel synthesis have over the synthesis of a primary amine using an alkyl halide and ammonia?

Give two names for each of the following nitriles: a. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{C} \equiv \mathrm{N}\) Equation Transcription: ? Text Transcription: CH_3 CH_2 CH_2 C trigram N

Which alkyl halides form the carboxylic acids listed here after reaction with sodium cyanide followed by heating the product in an acidic aqueous solution? a. butyric acid b. isovaleric acid c. cyclohexanecarboxylic acid

Problem 49P a. Propose a mechanism for the reaction of acetic anhydride with water. b. How does this mechanism differ from the mechanism for the reaction of acetic anhydride with an alcohol?

Problem 50P Propose a mechanism for the reaction of an acyl chloride with acetate ion to form an acid anhydride.

Problem 51P We have seen that acid anhydrides react with alcohols, water, and amines. In which of these reactions can the tetrahedral intermediate eliminate the carboxylate ion even if it does not lose a proton before the elimination step? Explain.

Problem 52P a. Propose a mechanism for the formation of succinic anhydride in the presence of acetic anhydride. b. How does acetic anhydride make it easier to form the anhydride?

Problem 53P One of the two polymers used for sutures shown in the box on Dissolving Sutures loses 50% of its strength in two weeks, and the other loses that much strength in three weeks. Which suture material lasts longer?

How would you synthesize the following compounds starting with a carboxylic acid?

Problem 55P Write a structure for each of the following: a. N,N-dimethylhexanamide b. 3,3-dimethylhexanamide c. cyclohexanecarbonyl chloride d. propanenitrile e. propionamide f. sodium acetate g. benzoic anhydride h. ?-valerolactone i. 3-methylbutanenitrile j. cycloheptanecarboxylic acid k. benzoyl chloride

Name the following compounds:

Problem 57P What products would be formed from the reaction of benzoyl chloride with the following reagents? a. sodium acetate b. water c. excess dimethylamine d. aqueous HCl e. aqueous NaOH f. cyclohexanol g. excess benzylamine h. 4-chlorophenol i. isopropyl alcohol j. excess aniline k. potassium formate

What products would be obtained from the following hydrolysis reactions?

a. List the following esters in order of decreasing reactivity in the first slow step of a nucleophilic addition-elimination reaction (formation of the tetrahedral intermediate): b. List the same esters in order of decreasing reactivity in the second slow step of a nucleophilic addition–elimination reaction (collapse of the tetrahedral intermediate).

Because bromocyclohexane is a secondary alkyl halide, both cyclohexanol and cyclohexene are formed when the alkyl halide reacts with hydroxide ion. Suggest a method to synthesize cyclohexanol from bromocyclohexane that would form little or no cyclohexene.

How could you use \({ }^{1} H\ N M R\) spectroscopy to distinguish among the following esters? Equation Transcription: Text Transcription: ^1 H NMR

Problem 63P If propionyl chloride is added to one equivalent of methylamine, only a 50% yield of N-methylpropanamide is obtained. If, however, the acyl chloride is added to two equivalents of methylamine, the yield of N -methylpropanamide is almost 100%. Explain these observations.

a. When a carboxylic acid is dissolved in isotopically labeled water (\(H_{2}{ }^{18} \mathrm{O}\)) and an acid catalyst is added, the label is incorporated into both oxygens of the acid. Propose a mechanism to account for this. b. If a carboxylic acid is dissolved in isotopically labeled methanol (\(\mathrm{CH}_{3}{ }^{18} \mathrm{OH}\)) and an acid catalyst is added, where will the label reside in the product? c. If an ester is dissolved in isotopically labeled water (\(H_{2}{ }^{18} \mathrm{O}\)) and an acid catalyst is added, where will the label reside in the product? Equation Transcription: Text Transcription: H_2 ^18 O Ch_3 ^18 OH

List the following compounds in order of decreasing frequency of the carbon–oxygen double-bond stretch:

Using an alcohol for one method and an alkyl halide for the other, show two ways to make each of the following esters: a. propyl acetate (odor of pears) b. isopentyl acetate (odor of bananas) c. ethyl butyrate (odor of pineapple) d. methyl phenylethanoate (odor of honey)

Problem 67P What reagents would you use to convert methyl propanoate into the following compounds? a. isopropyl propanoate b. sodium propanoate c. N-ethylpropanamide d. propanoic acid

Problem 68P What products would you expect to obtain from the following reactions? a. malonic acid + 2 acetyl chloride b. methyl carbamate + methylamine c. urea + water d. ?-ethylglutaric acid + acetyl chloride + ?

A compound with molecular formula \(\mathrm{C}_{5} \mathrm{H}_{10} \mathrm{O}_{2}\) gives the following IR spectrum. When it undergoes acid-catalyzed hydrolysis, the compound with the \({ }^{1} H\ N M R\) spectrum shown here is formed. Identify the compounds. Equation Transcription: Text Transcription: C_5 H_10 O_2 ^1 H NMR

Aspartame, the sweetener used in the commercial products NutraSweet and Equal, is \(200\) times sweeter than sucrose. What products would be obtained if aspartame were hydrolyzed completely in an aqueous solution of \(HCl\)? Equation Transcription: Text Transcription: 200 HCI

a. Which of the following reactions will not give the carbonyl product shown? b. Which of the reactions that do not occur can be made to occur if an acid catalyst is added to the reaction mixture?

\(1,4\)-Diazabicyclo[\(2.2 .2\)]octane (abbreviated DABCO) is a tertiary amine that catalyzes transesterii cation reactions. Propose a mechanism to show how it does this. Equation Transcription: Text Transcription: 1, 4 2.2.2

Two products, A and B, are obtained from the reaction of 1-bromobutane with \(\mathrm{NH}_{3}\) . Compound A reacts with acetyl chloride to form C, and compound B reacts with acetyl chloride to form D. The IR spectra of C and D are shown. Identify A, B, C, and D.

Problem 74P Phosgene (COCl2) was used as a poison gas in World War I. Give the product that would be formed from the reaction of phosgene with each of the following reagents: a. one equivalent of methanol b. excess methanol c. excess propylamine d. excess water

What reagent should be used to carry out the following reaction?

When a student treated butanedioic acid with thionyl chloride, she was surprised to find that the product she obtained was an anhydride rather than an acyl chloride. Propose a mechanism to explain why she obtained an anhydride.

What are the products of the following reactions?

When treated with an equivalent of methanol, compound A, with molecular formula \(\mathrm{C}_{4} \mathrm{H}_{6} \mathrm{Cl}_{2} \mathrm{O}\), forms the compound whose \({ }^{1} H\ N M R\) spectrum is shown here. Identify compound A. Equation Transcription: Text Transcription: C_4 H_6 C1_2 O ^1 H NMR

a. Identify the two products obtained from the following reaction: b. A student carried out the preceding reaction, but stopped it before it was half over, whereupon he isolated the major product. He was surprised to i nd that the product he isolated was neither of the products obtained when the reaction was allowed to go to completion. What product did he isolate?

Problem 80P An aqueous solution of a primary or secondary amine reacts with an acyl chloride to form an amide as the major product. However, if the amine is tertiary, an amide is not formed. What product is formed? Explain.

Identify the major and minor products of the following reaction:

Problem 82P a. A student did not obtain any ester when he added 2,4,6-trimethylbenzoic acid to an acidic solution of methanol. Why? (Hint: Build models.) b. Would he have encountered the same problem if he had tried to synthesize the methyl ester of 4-methylbenzoic acid in the same way?

When a compound with molecular formula \(\mathrm{C}_{11} \mathrm{H}_{14} \mathrm{O}_{2}\) undergoes acid-catalyzed hydrolysis, one of the products that is isolated gives the following \({ }^{1} H\ N M R\) spectrum. Identify the compound. Equation Transcription: Text Transcription: C_11 H_14 O_2 ^1 H NMR

Cardura, a drug used to treat hypertension, is synthesized as shown here. a. Identify the intermediate (\(A\)) and show the mechanism for its formation. b. Show the mechanism for conversion of \(A \text { to } B\). Which would be formed more rapidly, \(A \text { or } B\)? Equation Transcription: Text Transcription: A A to B A or B

a. If the equilibrium constant for the reaction of acetic acid and ethanol to form ethyl acetate is \(4.02\), what will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with equal amounts of acetic acid and ethanol? b. What will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with 10 times more ethanol than acetic acid? Hint: Recall the quadratic equation: for \(a x^{2}+b x+c=0\), \(x=\frac{-b \pm\left(b^{2}-4 a c\right)^{1 / 2}}{2 a}\) c. What will be the concentration of ethyl acetate at equilibrium if the reaction is carried out with \(100\) times more ethanol than acetic acid? Equation Transcription: Text Transcription: 4.02 ax^2 +bx+c=0 x=-b plus minus (b^2 -4ac)^1/2 /2a 100

The \({ }^{1} H\ N M R\) spectra for two esters with molecular formula \(\mathrm{C}_{8} \mathrm{H}_{8} \mathrm{O}_{2}\) are shown next. If each of the esters is added to an aqueous solution with a \(p H \text { of } 10\), which of the esters will be hydrolyzed more rapidly? Equation Transcription: Text Transcription: ^1 H NMR C_8 H_8 O_2 pH of 10

Show how the following compounds could be prepared from the given starting materials. You can use any necessary organic or inorganic reagents.

Is the acid-catalyzed hydrolysis of acetamide a reversible or an irreversible reaction? Explain.

The reaction of a nitrile with an alcohol in the presence of a strong acid forms an N-substituted amide. This reaction, known as the Ritter reaction , does not work with primary alcohols. a. Propose a mechanism for the Ritter reaction. b. Why does the Ritter reaction not work with primary alcohols? c. How does the Ritter reaction differ from the acid-catalyzed hydrolysis of a nitrile to form an amide?

The intermediate shown here is formed during the hydroxide-ion-promoted hydrolysis of the ester group. Propose a mechanism for the reaction.

The following compound has been found to be an inhibitor of penicillinase. The enzyme can be reactivated by hydroxylamine \(\left(\mathrm{NH}_{2} \mathrm{OH}\right)\). Propose a mechanism to account for the inhibition and for the reactivation. Equation Transcription: (NH2OH) Text Transcription: (NH_2OH)

Propose a mechanism that will account for the formation of the product.

Catalytic antibodies catalyze a reaction by forcing the conformation of the substrate in the direction of the transition state. The synthesis of the antibody is carried out in the presence of a transition state analog—a stable molecule that structurally resembles the transition state. This causes an antibody to be generated that will recognize and bind to the transition state, thereby stabilizing it. For example, the following transition state analog has been used to generate a catalytic antibody that catalyzes the hydrolysis of the structurally similar ester: a. Draw the transition state for the hydrolysis reaction. b. The following transition state analog is used to generate a catalytic antibody for the catalysis of ester hydrolysis. Draw the structure of an ester whose rate of hydrolysis would be increased by this catalytic antibody. c. Design a transition state analog that would catalyze amide hydrolysis at the amide group indicated.

Information about the mechanism of the reaction undergone by a series of substituted benzenes can be obtained by plotting the logarithm of the observed rate constant determined at a particular pH against the Hammett substituent constant \(\text { ( } \sigma \text { ) }\) for the particular substituent. The \(\sigma\) value for hydrogen is 0. Electron-donating substituents have negative \(\sigma\) values; the more strongly electron donating the substituent, the more negative its \(\sigma\) value will be. Electron-withdrawing substituents have positive \(\sigma\) values; the more strongly electron withdrawing the substituent, the more positive its \(\sigma\) value will be. The slope of a plot of the logarithm of the rate constant versus \(\sigma\) is called the \(\rho\) (rho) value. The \(\rho\) value for the hydroxide-ion-promoted hydrolysis of a series of meta- and para-substituted ethyl benzoates is \(+2.46\); the value for amide formation for the reaction of a series of meta- and para-substituted anilines with benzoyl chloride is \(-2.78\). a. Why does one set of experiments give a positive \(\rho\) value, whereas the other set of experiments gives a negative \(\rho\) value? b. Why were ortho-substituted compounds not included in the experiment? c. What would you predict the sign of the \(\rho\) value to be for the ionization of a series of meta- and para-substituted benzoic acids? Equation Transcription: Text Transcription: (sigma) sigma rho +2.46 -2.78

a. Which compound would you expect to have a higher dipole moment, methyl acetate or butanone? b. Which would you expect to have a higher boiling point?