Practice Exam #2

D

A simple chemical test to distinguish between acetone and 3-pentanone would be the reaction of the compounds with: A. base and methyl bromide. B. bromine with acetic acid. C. THF, LDA at -78 °C followed by reaction with bromine. D. bromine and aqueous hydroxide ion.

A

All of the following contain sp2 hybridized atoms in their functional group except: A. a nitrile. B. a carboxylic acid. C. an aldehyde. D. an anhydride.

B

An enzyme catalysed crossed aldol reaction forms the single stereoisomer of fructose 1,6-biphosphate shown below. What is the maximum number of possible stereosiomers? A. 3 B. 8 C. 2 D. 7

A

Arrange the following compounds in order of increasing boiling point, putting the compound with the lowest boiling point first. A. I < IV < II < III B. III < II < IV < I C. I < II < III < IV D. II < IV < I < III

B

Arrange the following compounds in order of increasing water solubility, putting the least soluble compound first. A. I < III < II < IV B. IV < II < III < I C. II < I < III < IV D. I < II < III < IV

B

For most compounds with a single keto group in the molecule, equilibrium favors the keto form over the enol form of the compound. This is due largely to what? A. The enol form can undergo intramolecular hydrogen bonding. B. The C=O bond is much stronger than the C=C bond. C. The C=C bond is much stronger than the C=O bond. D. The keto form can undergo intramolecular hydrogen bonding.

B

Glutamate can react with ATP to form an "activated glutamate". What is the structure of the "activated glutamate? A. I B. II C. III D. IV

C

How can you convert a carboxylic acid into an acid chloride? A. Heat with hydrochloric acid. B. React with sodium chloride. C. React with thionyl chloride (SOCl2). D. React with Cl2 and FeCl3.

C

If a Claisen condensation reaction is run using methyl propanoate as the reactant, NaOCH3 is the ideal base. Why is it important to use NaOCH3 and not NaOCH2CH3? A. NaOCH3 is a stronger base than NaOCH2CH3, and this reaction requires a stronger base. B. NaOCH3 is more soluble than NaOCH2CH3 in organic solvents, and this reaction requires a full equivalent of base to proceed. A full equivalent of NaOCH2CH3 would not dissolve, so the reaction would not proceed. C. Transesterfication can occur when esters react, and this transesterfication would result in a mixture of products. D. NaOCH3 is a weaker base than NaOCH2CH3, and this reaction requires a weaker base.

C

If you want to form a thermodynamic enolate, you want to: A. Use an aprotic solvent such as THF. B. Keep the reaction as cold as possible. C. Use a protic solvent such as ethanol. D. Use a carboxylic acid.

B

In a Michael reaction, where does the nucleophile attack the a,b-unsaturated carbonyl component? A. Carbonyl carbon B. b-Carbon C. a-Carbon D. Carbonyl carbon and b-carbon

B

In what situation can the yield of a single crossed Aldol product be increased? A. The electrophilic carbonyl carbon component is relatively hindered and is used in limited amount. B. The electrophilic carbonyl component is relatively unhindered and is used in excess. C. The nucleophilic carbonyl component is relatively hindered and is used in limited amount. D. The nucleophilic carbonyl component is relatively unhindered and is used in excess.

C

In what type of orbital does the lone pair on the indicated N atom reside? A. p B. sp C. sp2 D. sp3

D

In what type of orbital does the lone pair on the indicated N in viagra? A. s B. sp C. sp2 D. sp3

C

Of the carbonyl compounds; (1) benzaldehyde, (2) acetophenone and (3) dicyclohexylketone, which compound has no a-hydrogens? A. Acetophenone B. Acetone C. Benzaldehyde D. All of these compounds contain a-hydrogens.

A

Rank the following compounds in order of decreasing acidity, putting the most acidic first. A. II > I > III > IV B. IV > III > I > II C. IV > II > I > III D. II > I > IV > III

A

Rank the following compounds in order of increasing acidity, putting the least acidic first. A. I < IV < II < III B. III < IV < II < I C. I < II < III < IV D. III < II < IV < I

B

Rank the following compounds in order of increasing acidity, putting the least acidic first. A. I < II < III < IV B. IV < I < II < III C. I < IV < III < II D. III < II < I < IV

D

The following reaction is an example of what type of reaction? A. Claisen condensation B. Robinson annulation C. Mixed Aldol reaction D. Dieckmann condensation

D

The following reaction is an example of what type of reaction? A. Dieckmann condensation B. Robinson annulation C. Aldol self-condensation D. Michael reaction

B

The following represents a retro-Claisen reaction. What beta-diketone would produce tyrosine and phenylalanine as shown? A. I B. II C. III D. IV

A

The malonic ester synthesis can be adapted to synthesize a-amino acids by using diethyl acetamidomalonate as the starting material. Select the structure of the amino acid produced by the following synthesis: A. I B. II C. III D. IV

B

The reaction below is a direct enolate alkylation. It has been found that this reaction only works well with unhindered methyl and 1° alkyl halides. Pick the statement that best explains this observation. A. Hindered alkyl halides do not undergo SN1 reactions. B. Hindered alkyl halides do not undergo SN2 reactions. C. Methyl and 1° alkyl halides can form carbocations that can readily react with the nucleophilic enolate. D. The nucleophilic enolate requires a reaction center that has a positive charge.

D

The reaction below is an example of a biological aldol reaction. What is the correct product? A. I B. II C. III D. IV

A

Under basic conditions, the Aldol reaction is reversible, but dehydration is not. What is the reason for this difference in reactivity? A. The initial Aldol product is an alkoxide, so the reaction is not energetically downhill in either direction. B. The initial Aldol product is an alkoxide, so the reaction is energetically downhill going toward the starting materials. C. Water is a stable molecule. D. The initial Aldol product is an alkoxide, so the reaction is energetically downhill going toward the product.

C

What are the two starting materials for a Robinson annulation? A. a 1,5-Dicarbonyl compound and an enolate B. a 1,3-Dicarbonyl compound and an enolate C. an a,b-Unsaturated carbonyl compound and an enolate D. a b-Ketoester and an enolate

A

What cyclic product is formed in the intramolecular Aldol condensation when the following compound is treated with aqueous NaOH? A. I B. II C. III D. IV

D

What is (are) the product(s) of the following reaction? A. Only II B. Only I C. Only III D. Only I and III

B

What is an intramolecular Claisen reaction called? A. Michael reaction B. Dieckmann reaction C. Robinson reaction D. Hoffman reaction

B

What is the Aldol addition product formed from reaction of the following compound with itself? A. I B. II C. III D. IV

A

What is the Aldol addition product formed from the reaction of acetone, (CH3)2CO, with itself? A. I B. II C. III D. IV

B

What is the IUPAC name for the following compound? A. Methyl 3-methylbutanamide B. N-Methyl 3-methylbutanamide C. N-Methyl 3-methylhexanamide D. 5-Methylhexanamide

D

What is the IUPAC name for the following compound? A. Phenyl acetate B. Propionyl phenol C. Phenol propanoate D. Phenyl propanoate

D

What is the IUPAC name of the following compound? A. 2-Nitro-5-carboxychlorobenzene B. 2-Chloro-4-carboxynitrobenzene C. 2-Chloro-1-nitro-4-benzoic acid D. 3-Chloro-4-nitrobenzoic acid

B

What is the IUPAC name of the following compound? A. 3-Bromo-1-chloro-4-toluene B. 2-Bromo-4-chlorotoluene C. 4-Chloro-2-bromo-1-toluene D. 2-Bromo-4-chloroanisole

C

What is the common name of the following compound? A. 1,3-Propanedicarboxylic acid B. Propanedioic acid C. Malonic acid D. Succinic acid

B

What is the common name of the following compound? A. 2,3-Dimethoxyvaleric acid B. a,b-Dimethoxycaproic acid C. a,b-Dimethoxyvaleric acid D. 2,3-Dimethoxycaproic acid

C

What is the correct IUPAC name of the following compound? A. 2-Methoxybutanoic acid B. 4-Methoxybutanoic acid C. 4-Methoxypentanoic acid D. 2-Methoxypentanoic acid

A

What is the correct IUPAC name of the following compound? A. 3,3,5-Trimethylcyclohexanecarboxylic acid B. 3,5,5-Trimethylcyclohexanecarboxylic acid C. 3,5,5-Trimethylcyclohexanoic acid D. 3,3,5-Trimethylcyclohexanoic acid

C

What is the correct IUPAC name of the following compound? A. 4,5-Dimethylcyclohexanecarboxylic acid B. 1,2-Dimethylcyclohexanecarboxylic acid C. 3,4-Dimethylcyclohexanecarboxylic acid D. 3,4-Dimethylcyclohexanoic acid

C

What is the correct assignment of the names of the following aromatic heterocycles? A. I = pyridine; II = pyrimidine; III = furan. B. I = pyrimidine; II =pyrrole; III = furan. C. I = pyridine; II = pyrrole; III = furan. D. I = pyrimidine; II = pyrrole; III = tetrahydrofuran.

A

What is the correct assignment of the names of the following substituted benzenes? A. I = Styrene; II = aniline; III = anisole. B. I = Toluene; II = anisole; III = styrene. C. I = Styrene; II = anisole; III = phenol. D. I = Toluene; II = aniline; III = anisole.

B

What is the correct nucleophile for the reaction? A. NH2 B. NH3 C. ATP D. CH3NK2

A

What is the direct product of the base-promoted hydrolysis of an ester? A. A carboxylic acid salt B. An amide C. A nitrile D. A carboxylic acid

A

What is the general name for the class of products formed in an Aldol condensation reaction? A. a,b-Unsaturated carbonyl compound B. b-Hydroxy carbonyl compound C. a,g-Unsaturated carbonyl compound D. b,g-Unsaturated carbonyl compound

C

What is the general name for the reaction product formed in an aldol addition reaction? A. g-Hydroxy carbonyl compound B. a-Hydroxy carbonyl compound C. b-Hydroxy carbonyl compound D. a,b-Hydroxy carbonyl compound

C

What is the general name of the product of a crossed Claisen reaction between a ketone and an ester? A. g-Dicarbonyl compound B. b-Keto ester C. b-Dicarbonyl compound D. a,b-Dicarbonyl compound

B

What is the hybridization of the carbon atom in a carboxy group? A. p B. sp2 C. sp D. sp3

C

What is the hybridization of the indicated N atom in the following compound? A. p B. sp C. sp2 D. sp3

C

What is the hybridization of the indicated N atom in the following compound? a. p b. sp *c. sp 2 d. sp 3

C

What is the hybridization of the indicated N atom in the molecule of caffeine reside? A. p B. sp C. sp2 D. sp3

A

What is the major product of the following reaction? A. I B. II C. III D. IV

B

What is the missing reagent for the following reaction? A. Br2/KOH B. Br2/HOAc C. Cl2/FeCl3 D. Br2/FeBr3

A

What is the name given to an Aldol reaction between two different carbonyl compounds? A. Crossed Aldol reaction B. Versatile Aldol reaction C. Multiple Aldol reaction D. Differential Aldol reaction

B

What is the name given to the Claisen reaction between two different esters? A. Multiple Claisen reaction B. Crossed Claisen reaction C. Versatile Claisen reaction D. Differential Claisen reaction

D

What is the name of the following compound? A. 2,6-Dimethylbenzene B. 5-Methyltoluene C. Anisole D. 1,3-Dimethylbenzene

A

What is the predominant form of methionine (pKa = 2.28 and 9.21) at pH 12? A. I B. II C. III D. IV

C

What is the product of the following Claisen reaction? A. I B. II C. III D. IV

D

What is the product of the following reaction? A. Hexanal B. Hexanoic acid C. 1-Hexanamide D. 1-Hexanamine

A

What is the product of the following reaction? A. I B. II C. III D. IV

B

What is the product of the following reaction? A. I B. II C. III D. IV

C

What is the product of the following reaction? A. I B. II C. III D. IV

D

What is the product of the following reaction? A. I B. II C. III D. IV

D

What is the starting material in the following reaction? A. I B. II C. III D. IV

B

What is the starting material required to accomplish the following transformation? A. I B. II C. III D. IV

B

What is the structure for 3-cyanocyclopentanone? A. I B. II C. III D. IV

A

What is the structure for acetic propanoic anhydride? A. I B. II C. III D. IV

A

What is the structure of X, product of the following reaction? A. I B. II C. III D. IV

A

What orbitals are used to form the bond indicated in the following molecule? A. Csp2¾ Csp2 B. Csp2¾ C2p C. C2p¾C2p D. Csp3¾Csp3

D

What orbitals are used to form the indicated bond? A. sp3 B. sp2 C. p D. sp3 and sp2

C

What physical property and reaction type are used by extraction as useful techniques to separate and purify mixtures of compounds? A. Physical property = boiling point; reaction type = acid-base reaction. B. Physical property = density; reaction type = oxidation-reduction. C. Physical property = solubility differences; reaction type = acid-base reaction. D. Physical property = solubility differences; reaction type = oxidation-reduction.

A

What product (including stereochemistry) is formed in the following intermolecular reaction? A. I B. II C. III D. IV

B

What reaction type is a Claisen reaction? A. Electrophilic addition B. Nucleophilic substitution C. Nucleophilic addition D. Electrophilic substitution

D

What reagent would you use for the following transformation? A. NaBH4 B. H2, Pd/C C. LiAlH4 D. DIBAL-H

A

What two groups make up the carboxylic acid group (RCOOH)? A. Carbonyl and hydroxyl B. Carbonyl oxide and hydrogen C. Carbon dioxide and hydrogen D. Carbon monoxide and hydroxyl

A

What would happen if a mixture of benzoic acid and cyclohexanol dissolved in CH2Cl2 is treated with aqueous NaOH solution? A. The salt of benzoic acid would dissolve in the aqueous layer while cyclohexanol would remain in the CH2Cl2 layer. B. Benzoic acid would remain in the CH2Cl2 layer, and cyclohexanol would dissolve in the aqueous layer. C. The salt of benzoic acid would remain in the CH2Cl2 layer while cyclohexanol would dissolve in the aqueous layer. D. Benzoic acid would dissolve in the aqueous layer while cyclohexanol would remain in the CH2Cl2 layer.

D

Which of the following is an enol form of the following compound? A. I B. II C. III D. IV

C

Where do the two noteworthy peaks of carboxylic acids appear in HNMR spectra? A. Between 6 and 9 ppm for the OH proton and 2-2.5 ppm for the protons on the a carbon to the carboxy group. B. Between 10 and 12 ppm for the OH proton and 1-1.5 ppm for the protons on the a carbon to the carboxy group. C. Between 10 and 12 ppm for the OH proton and 2-2.5 ppm for the protons on the a carbon to the carboxy group. D. Between 6 and 9 ppm for the OH proton and 1-1.5 ppm for the protons on the a carbon to the carboxy group.

C

Where is the carbonyl absorption found in the IR spectrum of a simple ester? A. 3800 cm-1 B. 2.5 ppm C. 1740 cm-1 D. 2250 cm-1

A

Which beta-ketothioester is formed by the following biological Claisen reaction? A. I B. II C. III D. IV

A

Which is the more stable form of acetophenone? A. Only II B. Only I C. Only III D. I and II are equally stable

C

Which is the most acidic proton in the following compound? A. I B. II C. III D. IV

A

Which is the unsaturated carbonyl compound formed in the dehydration of the following b-hydroxy carbonyl compound? A. I B. II C. I and II D. None of the above

C

Which of the following bases are strong enough to significantly deprotonate ethanol, CH3CH2OH (pKa = 16)? A. NaOH B. NaOCH2CH3 C. NaH D. NaOCH3

C

Which of the following bicyclic ring systems can be prepared by an intermolecular Robinson annulation? A. I B. II C. III D. IV

B

Which of the following cannot be the starting material for the following reaction? A. I B. II C. III D. IV

A

Which of the following carbonyl compounds does not undergo Aldol addition reactions when treated with aqueous sodium hydroxide? A. I B. II C. III D. IV

C

Which of the following compounds can undergo an Aldol with itself? A. I B. II C. III D. Both I and II

D

Which of the following compounds is an enol of compound X drawn below? A. Only II B. Only I C. Only III D. Only I and II

D

Which of the following compounds is aromatic? A. I B. II C. III D. IV

D

Which of the following compounds is most basic? A. I B. II C. III D. IV

B

Which of the following compounds is not aromatic? A. I B. II C. III D. IV

C

Which of the following compounds is the most acidic? A. 2-Butanone B. 3-Pentanone C. Ethyl acetoacetate D. 1-Butanol

B

Which of the following compounds would undergo racemization in the presence of a base? A. I B. II C. III D. IV

C

Which of the following four compounds is the most acidic? A. I B. II C. III D. IV

C

Which of the following heterocycles is not aromatic? A. I B. II C. III D. IV

D

Which of the following heterocyclic compounds is aromatic? A. I and IV B. II, III, and IV C. I and III D. II and III

D

Which of the following ions is aromatic? A. Only I and II B. Only II and III C. Only III and IV D. Only II and IV

A

Which of the following is a lactam? A. I B. II C. III D. IV

D

Which of the following is not one of the Hückel's criteria for aromaticity? A. The molecule must be cyclic. B. The molecule must be planar. C. The molecule must be completely conjugated. D. The molecule must have 4n pi electrons.

D

Which of the following is the correct IUPAC name for the following structure? A. Potassium propanoate B. Potassium propanoic C. Butanoic potassium D. Potassium butanoate

D

Which of the following is the intermediate for halogenation of ketones under acidic conditions? A. A tautomer B. An epimer C. An enolate D. An enol

C

Which of the following molecules has the most acidic hydrogen atoms? A. I B. II C. III D. IV

D

Which of the following reaction conditions can be used to synthesize an ester (RCOOR')? A. RCOCl + R'NH2 + pyridine B. RCONH2 + R'OH C. RCOOH + R'OH + OH- D. RCOOH + R'OH + H+

B

Which of the following reagents can accomplish the transformation below? A. [1] O3; [2] H2O B. K2Cr2O7, H2SO4, H2O C. PCC, CH2Cl2 D. [1] LiAlH4, THF; [2] H2O

A

Which of the following statements about Aldol reactions with either aldehydes or ketones is true? A. Equilibrium favors the products with aldehydes; equilibrium favors the starting materials with ketones. B. Equilibrium favors the starting materials with aldehydes; equilibrium favors the products with ketones. C. Equilibrium favors the starting materials with both aldehydes and ketones. D. Equilibrium favors the products with both aldehydes and ketones.

B

Which of the following statements about the Henderson-Hasselbalch Equation is false? A. When the pH of the solution is lower than the pka of the acid, the acid will predominate of the base. B. When the pH of the solution equals the pKa of the acid, the acid (HA) and base (A:-) concentrations will be equal. C. When the pH of the solution is higher than the pKa of the acid, the base concentration will be lower than the acid concentration. D. When the pH of the solution is lower than the pKa of the acid, the concentration of acid will be higher than the concentration of the base.

D

Why can't you prepare 2-tert-butylcyclohexanone by the following reaction A. Because tert-butyl bromide is not a stable compound. B. Because tert-butyl bromide is a nucleophile. C. Because tert-butyl bromide is too basic. D. Because tert-butyl bromide cannot undergo an SN2 reaction.

D

Which of the following structures is the major contributor to the resonance hybrid of the phenoxide anion? A. I B. II C. III D. IV

A

Why are the nitrogen lone pair electrons on pyridine not included in the count of pi electrons, but the nitrogen lone pairs on pyrrole does get included? A. The nitrogen of pyridine is part of a double bond, so the p orbital is already filled and cannot accept more electrons. B. The five membered ring of pyrrole allows more space for the lone pair to be in line with the pi system. C. The nitrogen lone pair can be added to the pie system of pyridine, but then it was have 8 electrons and be antiaromatic.

D

Why doesn't nucleophilic acyl substitution stop at the tetrahedral intermediate? A. The leaving group is unstable and wants to be negatively charged. B. The nucleophile is too basic. C. There is no tetrahedral intermediate. D. Reforming the carbonyl is energetically favorable

B

Why is pyridine included in the reaction of an acid chloride and an amine or alcohol? A. Pyridine will absorb the heat of the reaction. B. Pyridine will neutralize the acid by-product of the reaction. C. Pyridine will protonate the carbonyl of the acid chloride, making it more reactive. D. Pyridine will deprotonate the amine or alcohol, making it a better nucleophile.

D

Why is the following compound not aromatic? A. It has 4n pi electrons. B. It is not cyclic. C. It has 4n+2 pi electrons. D. The p electron system is not continuous.

A

Will acetophenone be completely deprotonated by lithium diisopropylamide (LDA)? A. Yes B. No

A

Will the following reaction occur? A. Yes B. No

B

You see an absorption at 2250 cm-1 in the IR spectrum of a compound. What kind of functional group is present? A. An aldehyde B. A nitrile C. An ester D. A ketone

D

n-Butanenitrile will undergo all of the following listed reactions except one. Which reaction listed is not true for n-butanenitrile? A. n-Butanenitrile with be reduced to butyl amine in the presence of LiAlH4 with an aqueous work-up. B. n-Butanenitrile is hydrolyzed in the presence of acid to form butanoic acid. C. n-Butanenitrile is reduced with DIBAL-H to form n-butanal. D. n-Butane nitrile will react with ethylmagnesium bromide to form an alcohol.