Organic Chemistry
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Determine the major product of the reaction below.
Draw the major product of the reaction shown below.
Edman's degradation of a peptide forms thiazoline which can undergo rearrangement in dilute acid to phenylthiohydantoin (PTH) amino acid. Propose a mechanism for the rearrangement of the thiazoline shown below. (Hint: Thioesters react readily with nucleophiles.)
Complete the given reactions.
Identify the reagent(s) that can be used in the following reaction.
Draw the substitution product(s) of the given reaction.
The reaction of an acyl chloride with an aqueous solution of primary or secondary amine forms an amide as the major product. Predict the product formed when acetyl chloride reacts with trimethylamine.
Acetic acid is dissolved in isotopically labeled water (H 2O18) with an acid catalyst. Draw the labeled product(s) formed.
Provide the major substitution product(s) of the reaction below.
What neutral nucleophile would you use to convert methyl propionate into N-ethylpropionamide?
Determine the identity of the major products obtained in the reaction between benzoyl chloride and each of the compounds shown below.
(i) methanol
(ii) potassium acetate
(iii) 2-methylaniline
Suggest a mechanism for this nucleophilic acyl substitution.
Show how to make each of the compounds shown below using the appropriate acyl chlorides and amines as your starting materials.
Determine the identity of products obtained in each of the reactions shown below.
Suggest a plausible mechanism for the reaction shown below.
Under mild conditions, which of the proposed reactions below would take place quickly?
Show how to synthesize each of the compounds below using appropriate acyl chlorides and alcohols as the starting materials.(i) methyl propionate(ii) phenyl 2-methylhexanoate
Give the structures of the products and suggest a plausible mechanism for the reaction shown below.
Using an acid chloride as an intermediate, provide a reaction scheme to synthesize N-cyclopentylcyclopentanecarboxamide from cyclopentanecarboxylic acid and cyclopentanamine.
Provide a reaction scheme for the conversion of the given starting material to the nitrile shown below:
2-cyclohexylacetic acid → 2-cyclohexylacetonitrile
Propose a plausible synthesis that would efficiently carry out the following conversion. Use any necessary additional reagents.
Provide a reaction scheme for synthesizing the compound below, using the suitable carboxylic acid and amine.
Propose a reaction scheme for the synthesis of the specified compound below, utilizing the suitable carboxylic acid and amine.
Provide a plausible synthetic scheme for the following compound, which can be synthesized from a suitable carboxylic acid and amine.
Demonstrate how to synthesize the esters below from suitable alcohols and acyl chlorides:
i)
ii)
Illustrate the use of suitable amines and acyl chlorides to synthesize the amides below:
Demonstrate the use of propionic anhydride and a suitable amine or alcohol to yield the following:
Provide a reaction scheme to synthesize the following compounds. Note: The reaction scheme may involve more than one step.
(i) cyclopentanamine → N-cyclopentylacetamide
(ii) bromocyclopentane → dicyclopentylmethanol
What is the product of the reaction below?
Draw the structures of the expected products for the reaction below.
Draw the structure of the product formed from the reaction below.
Give the structure of the product formed from the reaction below.
Provide a reaction scheme to accomplish the synthesis shown below in good yield.
Phosgene is the acid chloride of carbonic acid. It can react twice just like other acid chlorides.
What is the product of the reaction of phosgene with excess butan-1-ol?
(i) The addition of one mole of 3-methylbutanoyl chloride to a liter of triethylamine resulted in a vigorous exothermic reaction. What is the mechanism for this reaction?
(ii) Once the previous mixture has cooled, one mole of propan-1-ol is added. This resulted in another vigorous exothermic reaction that produced triethylamine, triethylammonium chloride, and propyl 3-methylbutanoate. What is the mechanism for this reaction?
Propose a mechanism for the reaction between 3-methylbenzoic acid and propionyl chloride to yield 3-methylbenzoic propionic anhydride and hydrochloric acid. Let the oxygen in the hydroxyl group of 3-methylbenzoic acid serve as the nucleophile to attack the carbonyl carbon of the propionyl chloride.
Suggest a mechanism for the reaction between m-toluidine and methyl acetate to yield N-(m-tolyl)acetamide and methanol. In the proposed mechanism, identify the leaving group and determine whether it is suitable for an SN2 reaction.
Outline a mechanism when benzyl propionate and isopropylamine react. Include the structure of the transition state when the leaving group departs. Also, identify the nucleophile and the leaving group.
Consider the following acid-catalyzed reaction:
Suggest a mechanism for the reaction. Why does a drop of sulfuric acid significantly speed up the rate of the reaction?
Describe how the following compounds can be synthesized using anhydride as a starting material. Why is an anhydride a more suitable starting material than an acid chloride?
(i) glutaric acid monamide
(ii) glutaric acid monoethyl ester
Determine the major products obtained from the reaction of cyclopentanecarbonyl chloride with each of the reagents listed below:
(i) toluene and aluminum chloride, followed by water
(ii) excess cyclopentylmagnesium bromide followed by treatment with a dilute acid
(iii) LiAlH(O-t-Bu)3
Arrange the carboxylic acid derivatives listed below in decreasing order of reactivity toward nucleophilic attack at C=O with a strong nucleophile like methoxide.
Propose the most appropriate reactants to use for the conversion below.
Show the products formed in the reactions given below.
(1)
(2)
Diethyl carbonate is an easy-to-handle liquid reagent that is widely utilized in synthesis. Show how you would synthesize propoxur insecticide using diethyl carbonate as the starting material.
The reaction shown below converts the carboxylic acid into an N-hydroxysuccinimide (NHS) ester to activate it for coupling with an amine. Is a NHS ester more reactive than a simple alkyl ester? Why?
4-acetylbenzoic acid is an isomer of aspirin, an anti-inflammatory medicine. Show how you would synthesize 4-acetylbenzoic acid from phenol.
Propose the most appropriate reagent(s) to use for the following conversion.
Determine the product formed in the reaction given below:
ethoxy benzene + glutaric anhydride and aluminum chloride, followed by water
Propose the multistep synthesis of the following transformation. Use any necessary reagents and solvents.
What reagents are required to produce the following compound using the given starting material?
The Ritter reaction occurs when nitrile and alcohol react in the presence of an acid to form N-substituted amide. Provide an appropriate mechanism for the Ritter reaction depicted below.
The Ritter reaction occurs when nitrile and secondary or tertiary alcohol reacts in the presence of an acid to form N-substituted amide. Explain why the Ritter reaction does not work with primary alcohols.
The reaction of a nitrile with a secondary or tertiary alcohol to produce an N-substituted amide in the presence of an acid is called the Ritter reaction. The reaction includes the nucleophilic addition of a nitrile to a carbenium ion. What is the key difference between the Ritter reaction and the amide formation through acid-catalyzed hydrolysis of a nitrile?
i) Identify the reactions that will not produce the given carbonyl product.ii) Which reactions from part (i) will occur upon addition of an acid catalyst?
Explain why an acid cannot increase the rate of aminolysis of an ester.
Explain why a base cannot increase the rate of aminolysis of an ester.
A. Because the base would protonate the amine and it would lose its nucleophilicity.
B. Because the base would compete with the amine for the nucleophilic acyl substitution.
C. Because the base would deprotonate the amine and it would lose its nucleophilicity.
D. None of these.
Arrange the following esters in increasing order of their reactivity towards the first step of the nucleophilic acyl substitution.
Arrange the following esters in increasing order of their reactivity towards the second step of the nucleophilic acyl substitution.
Rank the following compounds by increasing reactivity of their C=O bond towards strong nucleophiles like ethoxide.
Show how you would convert 2-methylcyclohexanol to the following products.
a. 2-methylcyclohexylpropionate
b. 1-bromo-1-methylcyclohexane
Draw the product expected in the following multistep reaction.
Draw the product of the multistep synthesis reaction shown below.
Show how the following conversion can be accomplished.
Propose a synthetic pathway to produce each of the following compounds using an ester with no more than eight carbons and other necessary reagents.
Show how the following syntheses can be carried out by acylation–reduction of the given amines.
a. N-benzylpyrrolidine from pyrrolidine
b. N-ethylaniline from aniline
Determine the ion(s) that would produce an anhydride faster:
Determine the product formed in a reaction between propanamide and OH-. Hint: pKa(NH3) = 38.0, and pKa(H2O) = 15.7.
What would be the product of the acyl substitution reaction in which a weaker base than the substituent linked to the acyl group is used?
If the base is stronger than the substituent linked to the acyl group in the tetrahedral intermediate, determine the product of an acyl substitution reaction.
Given below is the table with the pKa values of the conjugate acids of several leaving groups. Based on the table, predict the product of the following reaction.
Using the pKa values provided in the table below, predict the product of the following reaction.
Which neutral nucleophile, starting with propionyl bromide, would you utilize to produce the following compound?
Which neutral nucleophile would be required to synthesize the compound given below if the starting material is propionyl bromide?
If propionyl bromide is chosen as the starting material, determine the neutral nucleophile needed to produce the following compound.
Determine the neutral nucleophile needed to produce the given compound from propionyl bromide.
Draw the mechanism of the aminolysis of p-tolyl acetate using ethylamine.
Illustrate the mechanism of the reaction between acetamide and methanol in an acid-catalyzed reaction to form an ester.
Illustrate the mechanism of the reaction between propionic anhydride and water.
Which of these reactions involves the loss of the carboxylate anion from the tetrahedral intermediate without deprotonation prior to the elimination step? Explain.
Suggest a suitable mechanism for the reaction between glutaric acid and ethanoic anhydride to form glutaric anhydride at a neutral pH.
Determine how ethanoic anhydride promotes the creation of glutaric anhydride.
What is the product formed in a reaction between 4-methylbenzoyl chloride and sodium hydroxide?
Which substances are produced when 4-methylbenzoyl chloride reacts with cyclopentanol?
Determine the product for the reaction of 4-methylbenzoyl chloride with isobutyl alcohol.
What is the product formed when 4-methylbenzoyl chloride reacts with sodium acetate?
What would be the product(s) formed for the hydrolysis reaction given?
Determine the product(s) formed in the given reaction at neutral pH.glutaric acid + propionyl chloride (2 eq.)
What would be the product(s) formed in the given reaction?
isopropyl carbamate + ethylamine
Show how the following conversion can be accomplished using any necessary reagents.
Propose a suitable mechanism for the reaction given below.
Methyl isobutyrate can be produced from isobutyric acid using diazomethane.
Does the following reaction mechanism correspond to this reaction?
Illustrate the mechanism of the reaction between propanoyl chloride and water to produce propanoic acid.
Illustrate the mechanism when di-tert-butyl dicarbonate, reacts with the simplest amino acid, glycine.
What is the product of the reaction shown below?
A carboxylic acid needs to be activated before it can be coupled with an amine. This is often achieved by converting the acid into an N-hydroxysuccinimide (NHS) ester as shown below. Suggest a mechanism for the transformation.
Provide a reaction scheme showing the synthesis of the ester compounds listed below from their corresponding acyl chloride and alcohol.
i. benzyl cyclopentanecarboxylate
ii. cyclopentyl cyclohexanecarboxylate
Determine the product produced by each of the reactions given below.
i. p-cresol + propionic anhydride
ii. p-cresol + acetic formic anhydride
A carboxylic acid can be activated for coupling with an amine by converting it to an N-hydroxysuccinimide (NHS) ester, as shown below. Suggest a mechanism for the reaction that occurs between ethanamine and the NHS ester.
Give the product of the reaction shown below:
Show how the following ketone can be produced by a Friedel-Crafts acylation using the given carboxylic acid.
Provide the product of the reaction shown below:
Phosgene is the acid chloride of carbonic acid. It can react twice, just like other acid chlorides. What is the product of the reaction of phosgene with 1 equivalent of ethanol, followed by 1 equivalent of cyclopentanamine?
Show how the following synthesis can be carried out:
cyclohexylmethanol → cyclohexylmethyl acetate
Show how the following synthesis can be accomplished. (Note: The conversion might involve multiple steps.)
benzoic acid → benzonitrile
Show how the following transformation can be accomplished:
3-methylbutan-2-amine → N-(3-methylbutan-2-yl)formamide