Organic Chemistry - Exam #3
Draw a structure for the transition state of the following reaction. Include correct partial charges
Section: 8.7
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail
Section: 8.7
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.7
Provide the structure of the major organic product of the reaction below.
Section: 8.7
Complete the following reaction and provide a detailed, step-by-step mechanism for the process.
Section: 8.8
Draw the line energy orbital diagram for the outer shell of an sp2 hybridized carbon atom and explain how a carbon/carbon double is formed.
If we follow Hund's rule and fill each orbital with one electron and then promote one to the lone atomic p orbital, there are single electrons in the three sp hybrid orbitals that can form sigma overlaps with 2-H orbitals and one other sp2 hybridized carbon orbital. The atomic p orbital with one electron can then form a pi bond by a side to side overlap with the other p orbital from the other sp2 hybridized carbon atom. Section: 7.2
Provide the major organic product of the reaction below.
Section: 8.15
Provide the structure of the product which results when the alkene below is treated with O3 followed by (CH3)2S.
Section: 8.15
β-Ocimene is a natural product with a pleasant odor. Based on the information below, deduce the structure of β-ocimene.
Section: 8.15
When isobutylene [CH2C(CH3)2] is treated with BF3, polyisobutylene is formed. Provide a step-by-step mechanism for this polymerization reaction.
Section: 8.16
Complete the following reaction and provide a detailed, step-by-step mechanism for the process.
Section: 8.3
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.3
Draw the major regioisomeric product generated in the reaction below.
Section: 8.3
Provide the major organic product of the reaction below.
Section: 8.3
Provide the structure of the major organic product of the reaction below.
Section: 8.3
When 3,6-dimethylcyclohexene is reacted with dry gaseous HBr, one of the products is 1-bromo-1,4-dimethylcyclohexane. Provide a detailed step-by-step mechanism to explain the formation of this product
Section: 8.3
When propylene reacts with hydrogen bromide in the presence of a peroxide initiator, which of the following structures are formed during the mechanism? A) B) C) D) H∙
Section: 8.3
Complete the following reaction and provide a detailed, step-by-step mechanism for the process
Section: 8.4
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.4
Draw the major organic product(s) generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.4
Provide the structure of the major organic product of the reaction below.
Section: 8.4
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail
Section: 8.5
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.5
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.6
Provide the structure of the major organic product of the reaction below.
Section: 8.6
Complete the following reaction by filling in the appropriate reagents.
Section: 8.7
What products result when calcium carbide is combined with water?
acetylene and calcium hydroxide
Name the compound which results when pent-1-yne is treated with sodium in liquid ammonia.
pent-1-ene
Name the compound which results when pent-2-yne is subjected to catalytic hydrogenation using a platinum catalyst.
pentane
How many moles of water are produced when one mole of propyne undergoes complete combustion?
two
Name the alkene shown. Be sure to include the appropriate E or Z label necessary
(E)-1-bromo-4-chlorohept-3-ene Section: 7.5
Name the compound shown below
2-propyl-1,3-cyclopentadiene or 2-propylcyclopenta-1,3-diene Section: 7.4
What major organic product results when 3-octyne is treated with sodium metal in liquid ammonia? A) (E)-3-octene B) (Z)-3-octene C) 1-octyne D) 1-octene E) octane
A) (E)-3-octene
How many distinct alkynes exist with a molecular formula of C4H8? A) 0 B) 1 C) 2 D) 3 E) 4
A) 0
A mixture of hept-1-yne, hept-2-yne, and hept-3-yne was hydrogenated in the presence of a platinum catalyst until hydrogen uptake ceased. If one assumes that the hydrogenation went to completion, how many different seven-carbon hydrocarbons were produced? A) 1 B) 2 C) 3 D) 6 E) 8
A) 1
Which of the following alkynes has the lowest boiling point? A) 3,3-dimethyl-1-butyne B) 1-hexyne C) 2-hexyne D) 3-hexyne E) 1-decyne
A) 3,3-dimethyl-1-butyne
To a solution of propyne in diethyl ether, one molar equivalent of CH3Li was added and the resulting mixture was stirred for 0.5 hour. After this time, an excess of D2O was added. Describe the major organic product(s) of this reaction. A) CH3C≡CD + CH4 B) CH3C≡CCH3 C) CD3C≡CD3 D) CH3C≡CCD3 E) CH3C≡CD + CH3D
A) CH3C≡CD + CH4
Which of the following reagents should be used to convert an internal alkyne to an α-diketone? A) KMnO4, H2O, neutral B) O3 then H2O C) Sia2BH then H2O2 D) Na, NH3 E) HgSO4, H2SO4
A) KMnO4, H2O, neutral
Why is a terminal alkyne favored when sodium amide (NaNH2) is used in a elmination reaction with 2,3-dichlorohexane? A) The strong base deprotonates the terminal alkyne and removes it from the equilibrium. B) The resonance favors the formation of the terminal rather than internal alkyne. C) The positions of the Cl atoms induce the net formation of the terminal alkyne. D) The terminal alkyne is more stable than the internal alkyne and is naturally the favored product. E) The terminal alkyne is not favored in this reaction.
A) The strong base deprotonates the terminal alkyne and removes it from the equilibrium.
What class of organic product results when 1-heptyne is reacted with disiamylborane followed by treatment with basic hydrogen peroxide? A) aldehyde B) ketone C) diol D) ether E) carboxylic acid
A) aldehyde
Complete the following reaction by filling in the necessary reagents.
Answer: Section: 8.15
Provide a series of steps through which 2-methylbutane is converted into 2-methylbut-1-ene?
Answer: 1. Br2, hn 2. (CH3)3CO- Section: 7.9
Provide the reagents necessary for carrying out the transformation of 2-methylheptane to 2-methylhept-1-ene
Answer: 1. Br2, hν 2. (CH3)3CO- K+, (CH3)3COH Section: 7.9
Provide the reagents necessary to complete the following transformation.
Answer: 1. Br2, hν 2. H2O, Δ or 1. Br2, hν 2. NaOCH3, CH3OH 3. H3O+ or Hg(OAc)2, H2O; NaBH4 Section: 8.4
Provide the reagents necessary to complete the following transformation.
Answer: 1. Br2, hν 2. NaOCH3, CH3OH 3. CH2I2, Zn(Cu) Section: 8.11
Provide the reagents necessary for carrying out the transformation of 2-methylheptane to 2-methylhept-2-ene.
Answer: 1. Br2, hν 2. NaOH, acetone Section: 7.9
Provide the reagents necessary for carrying out the transformation of cyclopentane to cyclopentene.
Answer: 1. Br2, hν 2. NaOH, acetone Section: 7.9
Provide the reagents necessary to complete the following transformation.
Answer: 1. NaOCH3, CH3OH 2. MCPBA or CH3CO3H 3. H3O+ or -OH Section: 8.13
Provide the reagents necessary to complete the following transformation.
Answer: 1. NaOCH3, CH3OH 2. OsO4, H2O2 or cold, dilute KMnO4, -OH Section:8.14
Provide the reagents necessary to convert 3-methyl-2-butanol to 2-methyl-2-butanol.
Answer: 1. conc. H2SO4 2. H3O+ or Hg(OAc)2, H2O followed by NaBH4 or 1. PBr3 2. NaOCH3, CH3OH 2. H3O+ or Hg(OAc)2, H2O followed by NaBH4 Section: 8.6
Give the structure of the alkene which would yield the following products upon ozonolysis-reduction. CH3COCH3 + CH3CH2CHO
Answer: (CH3)2CCHCH2CH3 Section: 8.15
Provide the proper IUPAC name for the alkene shown below.
Answer: (E)-2-ethylhexa-1,4-diene Section: 7.5
Provide the name of the major alkene product that results when (2S,3R)-2,3-dibromopentane is treated with zinc in acetic acid.
Answer: (E)-2-pentene Section: 7.9
Which has the smaller heat of hydrogenation, (E)-2-pentene or (Z)-2-pentene? What is the structural origin of this difference?
Answer: (E)-2-pentene has the smaller heat of hydrogenation. There is less steric strain between the alkyl substituents in the (E)-isomer than in the (Z)-isomer. Section: 7.7
Provide the proper IUPAC name for the alkene shown below.
Answer: (E)-3,4-dimethylhept-3-ene Section: 7.5
Provide the proper IUPAC name for the alkene shown below.
Answer: (E)-3,5-dimethylhex-2-ene Section: 7.5
Provide the name of the major alkene product that results when (2S,3S)-2-bromo-3-methylpentane is treated with sodium methoxide in methanol.
Answer: (E)-3-methyl-2-pentene Section: 7.9
Provide the proper IUPAC name for the alkene shown below.
Answer: (R)-3-ethyl-3-methylcyclohexene Section: 7.4
Provide the name of the major alkene product that results when (2R,3R)-2,3-dibromopentane is treated with zinc in acetic acid.
Answer: (Z)-2-pentene Section:7.9
Provide the name of the major alkene product that results when (2S,3R)-2-bromo-3-methylpentane is treated with sodium methoxide in methanol.
Answer: (Z)-3-methyl-2-pentene Section: 7.9
Provide the proper IUPAC name for the alkene shown below.
Answer: (Z)-5-chloropent-2-ene Section: 7.5
Draw the structure of poly(tetrafluoroethylene) or Teflon.
Answer: -[CF2CF2]n- Section: 7.6
Draw the structure of polyethylene.
Answer: -[CH2CH2]n- Section: 7.6
What alkene, which contains no oxygen atoms and a single CC, will give CH3CO(CH2)4CHO upon treatment with OsO4 followed by cleavage with periodic acid?
Answer: 1-methylcyclohexene Section: 8.15
Which of the following alkenes can show geometric isomerism: 2,3-dichloro-2-pentene 4-chloro-3-ethyl-3-hexene, 3-chloro-2-methyl-2-butene 3-chloro-2-methyl-1-butene
Answer: 2,3-dichloro-2-pentene Section: 7.4
Name the major alcohol product which results when 3,3-dimethylbut-1-ene is treated with dilute acid.
Answer: 2,3-dimethyl-2-butanol Section: 8.4
Provide an acceptable name for (CH3)2CHCH=C(CH3)CH2CH3.
Answer: 2,4-dimethyl-3-hexene or 2,4-dimethylhex-3-ene Section: 7.4
Name the alkene shown. Be sure to include the appropriate E or Z label necessary.
Answer: 2,5-dichloropent-1-ene Section: 7.4
Name the major product which results when HBr is added to 3-ethyl-3-hexene.
Answer: 3-bromo-3-ethylhexane Section: 8.3
The compound produced when 3-methylpent-2-ene undergoes hydrogenation in the presence of a platinum catalyst is ________.
Answer: 3-methylpentane Section: 7.7
Provide an acceptable name for (CH3CH2)2CHCH2CH=CH2.
Answer: 4-ethyl-1-hexene or 4-ethylhex-1-ene Section: 7.4
Provide a correct IUPAC name for the structure below.
Answer: 5-bromo-2-methyl-1,3-cyclopentadiene Section: 7.4
Provide the proper IUPAC name for the alkene shown below.
Answer: 6-bromo-1-methylcyclohexene Section: 7.4
The trans isomers of cycloalkenes with rings containing fewer than ________ atoms are unstable at room temperature.
Answer: 8 Section: 7.7
Predict the major product of the reaction shown below. A) 2,3-dimethyl-2-butene B) 2,3-dimethyl-1-butene C) 3,3-dimethyl-1-butene D) None of the above
Answer: A Section: 7.10
For which of the following alkenes will cis- and trans- isomers not exist? A) a) only B) b) only C) both a) and c) D) d) only E) both c) and d)
Answer: A Section: 7.5
Which of the following best describes the geometry about the carbon-carbon double bond in the alkene below? A) E B) Z C) neither E nor Z
Answer: A Section: 7.5
Using Zaitsev's rule, choose the most stable alkene among the following. A) 1,2-dimethylcyclohexene B) 1,6-dimethylcyclohexene C) cis-3,4-dimethylcyclohexene D) They are all of equal stability according to Zaitsev's rule.
Answer: A Section: 7.7
Using Zaitsev's rule, choose the most stable alkene among the following. A) 1-methylcyclohexene B) 3-methylcyclohexene C) 4-methylcyclohexene D) They are all of equal stability according to Zaitsev's rule.
Answer: A Section: 7.7
Which of the following alkenes has the smallest molar heat of hydrogenation (ie, releases the least heat upon hydrogenation)? A) 2,3-dimethyl-2-butene B) 2-methyl-2-butene C) trans-2-butene D) cis-2-butene E) 1-hexene
Answer: A Section: 7.7
Which sequence ranks the following compounds in order of increasing heat of hydrogenation, ΔHhyd? 1) cis-2-butene 2) 1-butene 3) cyclohexene A) 3<1<2 B) 3<2<1 C) 2<1<3 D) 1<3<2
Answer: A Section: 7.7
Which of the following alkenes is the major product when 2-bromo-2-methylpentane is treated with potassium tert-butoxide in tert-butanol? A) 2-methylpent-1-ene B) 2-methylpent-2-ene C) (E)-4-methylpent-2-ene D) (Z)-4-methylpent-2-ene E) 4-methylpent-1-ene
Answer: A Section: 7.9
________ is the use of an optically active reagent or catalyst to convert an optically inactive starting material into an optically active product. A) Asymmetric induction B) Racemization C) Optical reduction D) Meso effection E) Chiralization
Answer: A Section: 8.10
Which of the following steps would successfully complete the following reaction? A) I only B) II & III C) I & IV D) I, II, & IV
Answer: A Section: 8.12
A reaction of an unknown alkene with MCPBA in dichloromethane followed by work-up with H2O/H+ yielded, as the major product, a racemic mixture of (2S, 3S) and (2R, 3R)-3-methylpentan-2,3-diol. What is the specific structure of the alkene used in the reaction? A) (Z)-3-methylpent-2-ene B) (E)-3-methylpent- 2-ene C) 2-methylpent-2-ene D) 2,3-dimethylbut-2-ene E) none of the above
Answer: A Section: 8.13
An unknown compound with empirical formula C3H5 was treated with Br2/CCl4. The bromine solution went from orangish/red to clear immediately at room temperature. Upon treatment with O3 followed by work-up with dimethylsulfide the following products were identified. From the information provided what is/are the most likely structure(s) for this unknown compound.
Answer: A Section: 8.15
What is the expected product of the following reaction?
Answer: A Section: 8.17
When an alkene is subjected to treatment with Hg(OAc)2 in alcohol followed by reaction with NaBH4, what new class of compound is formed? A) ether B) epoxide C) alkane D) syn diol E) alkyne
Answer: A Section: 8.6
Provide the reagents necessary to complete the following transformation. A) 1. BH3∙THF 2. H2O2, HO- B) H2O, H2SO4 C) OsO4, H2O2 D) CH3CO3H E) 1. CH3CO3H 2. H+, H2O
Answer: A Section: 8.7
Addition of Br2 to (E)-hex-3-ene produces ________. A) a meso dibromide B) a mixture of enantiomeric dibromides which is optically active C) a mixture of enantiomeric dibromides which is optically inactive D) (Z)-3,4-dibromo-3-hexene E) (E)-3,4-dibromo-3-hexene
Answer: A Section: 8.8
Which of the following best describes the geometry about the carbon-carbon double bond in the alkene below? A) E B) Z C) neither E nor Z
Answer: A Section: 7.5
Which of the following statements best describes the relative bond dissociation energies of the sigma and pi bonds present in the carbon-carbon double bond of an alkene? A) sigma > pi B) pi > sigma C) sigma = pi D) cannot be estimated
Answer: A Section: 7.1
Consider molecules with the formula C10H16. Which of the following structural features are not possible within this set of molecules? A) 2 triple bonds B) 1 ring and 1 triple bond C) 2 rings and 1 double bond D) 2 double bonds and 1 ring E) 3 double bonds
Answer: A Section: 7.3
What olefin metathesis products result when 1-hexene is treated with Grubbs catalyst? What provides the thermodynamic driving force for this reaction?
Answer: A mixture of (E)- and (Z)-5-decene products results. The thermodynamic driving force is the removal of the volatile ethylene by-product. Section: 8.17
Which of the following additions to alkenes occur(s) specifically in an anti fashion? A) hydroboration-oxidation B) addition of Br2 C) addition of H2 D) addition of H2O in dilute acid E) both A and B
Answer: B Diff: 1 Section: 8.8
Dehydration of an unknown alcohol with concentrated H2SO4 results in the formation of all of the following alkene products. What is/are the possible structures of the original alcohol?
Answer: B Section: 7.10
Which of the following best describes the geometry about the carbon-carbon double bond in the alkene below? A) E B) Z C) neither E nor Z
Answer: B Section: 7.5
Consider the constitutional isomers 2-methylbut-1-ene, 2-methylbut-2-ene, and 3-methylbut-1-ene. When each of these alkenes is subjected to catalytic hydrogenation (H2, Pt), a single product results. Which of the following best describes the structural relationship among these products? A) The products are cis-trans isomers. B) The products are identical. C) The products are constitutional isomers. D) The products are enantiomers. E) The products are diastereomers.
Answer: B Section: 7.7
Using Zaitsev's rule, choose the most stable alkene among the following. A) hex-1-ene B) (E)-hex-2-ene C) (Z)-hex-2-ene D) They are all of equal stability according to Zaitsev's rule.
Answer: B Section: 7.7
Which of the following compounds is an E isomer? A) B) C) D)
Answer: B Section: 7.7
Alkenes ________. A) are relatively polar compounds B) have lower boiling points than alcohols of similar molecular weight C) are reasonably soluble in water D) both A and B E) none of the above
Answer: B Section: 7.8
Which of the following alkenes is the major product when 2-bromo-2-methylpentane is treated with sodium ethoxide in ethanol? A) 2-methylpent-1-ene B) 2-methylpent-2-ene C) (E)-4-methylpent-2-ene D) (Z)-4-methylpent-2-ene E) 4-methylpent-1-ene
Answer: B Section: 7.9
Treatment of cyclopentene with peroxybenzoic acid ________. A) results in oxidative cleavage of the ring to produce an acyclic compound B) yields a meso epoxide C) yields an equimolar mixture of enantiomeric epoxides D) gives the same product as treatment of cyclopentene with OsO4 E) none of the above
Answer: B Section: 8.12
Predict the major product of the following reaction.
Answer: B Section: 8.3
Provide the reagents necessary to complete the following transformation. A) 1. BH3∙THF 2. H2O2, HO- B) H2O, H2SO4 C) OsO4, H2O2 D) CH3CO3H E) 1. CH3CO3H 2. H+, H2O
Answer: B Section: 8.4
Which of the following intermediates is thought to occur in the mechanism by which alkenes are hydrated in the presence of acid? A) carbanion B) carbocation C) free radical D) carbene E) alkyne
Answer: B Section: 8.4
What synthetic goal is achieved by subjecting an alkene to an oxymercuration-demercuration sequence? A) Markovnikov addition of H2O wherein skeletal rearrangement is promoted B) Markovnikov addition of H2O wherein skeletal rearrangement is prevented C) anti-Markovnikov addition of H2O wherein skeletal rearrangement is promoted D) anti-Markovnikov addition of H2O wherein skeletal rearrangement is prevented E) syn-hydroxylation
Answer: B Section: 8.5
Both (E)- and (Z)-hex-3-ene can be subjected to a hydroboration-oxidation sequence. How are the products from these two reactions related to each other? A) The (E)- and (Z)-isomers generate the same products but in differing amounts. B) The (E)- and (Z)-isomers generate the same products in exactly the same amounts. C) The products of the two isomers are related as constitutional isomers. D) The products of the two isomers are related as diastereomers. E) The products of the two isomers are not structurally related
Answer: B Section: 8.7
Which of the following alkenes will yield a meso dihalide when reacted with Br2/CCl4 at room temperature?
Answer: B Section:8.8
The carbon-carbon bond length in ethylene is ________ than the carbon-carbon bond length in ethane, and the HCH bond angle in ethylene is ________ the HCH bond angle in ethane A) shorter; smaller than B) shorter; larger than C) longer; smaller than D) longer; larger than E) longer; the same as
Answer: B Section: 7.2
What two atomic orbitals or hybrid atomic orbitals overlap to form the CH bond in ethylene? A) C sp3 + H s B) C sp2 + H s C) C sp + H s D) C p+H s
Answer: B Section: 7.2
A chemist has isolated a new natural product and determined its molecular formula to be C24H40O4. In hydrogenation experiments the chemist found that each mole of the natural product reacted with two moles of H2. How many rings are present in the structure of the new natural product? A) 2 B) 3 C) 4 D) 5 E) 6
Answer: B Section: 7.3
A newly isolated natural product was found to have the molecular formula C15H28O2. By hydrogenating a sample of the compound, it was determined to possess one p bond. How many rings are present in the compound? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: B Section: 7.3
How many elements of unsaturation are implied by the molecular formula C6H12? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: B Section: 7.3
How many elements of unsaturation do molecules with a molecular formula of C6H6Cl6 have? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: B Section: 7.3
Identify the correct name for the following structure. A) 3-methoxy-5-methylcyclohepta-1,5-diene B) 6-methoxy-1-methylcyclohepta-1,4-diene C) 7-methoxy-5-methylcyclohepta-1,4-diene D) 4-methoxy-2-methylcyclohepta-1,5-diene
Answer: B Section: 7.4
Which of the following best describes the geometry about the carbon-carbon double bond in the alkene below? A) E B) Z C) neither E nor Z
Answer: C Section: 7.5
Which of the alkyl chlorides listed below undergoes dehydrohalogenation in the presence of a strong base to give pent-2-ene as the only alkene product? A) 1-chloropentane B) 2-chloropentane C) 3-chloropentane D) 1-chloro-2-methylbutane E) 1-chloro-3-methylbutane
Answer: C Section: 7.9
Provide the reagents necessary to complete the following transformation. A) 1. BH3∙THF 2. H2O2, HO- B) H2O, H2SO4 C) OsO4, H2O2 D) CH3CO3H E) 1. CH3CO3H 2. H+, H2O
Answer: C Section: 8.14
How many moles of carbon dioxide are generated when one mole of the compound shown is treated with warm, concentrated KMnO4? A) 1 B) 2 C) 3 D) 4 E) 8
Answer: C Section: 8.15
HBr can be added to an alkene in the presence of peroxides (ROOR). What function does the peroxide serve in this reaction? A) nucleophile B) electrophile C) radical chain initiator D) acid catalyst E) solvent
Answer: C Section: 8.3
Which of the following is the best reaction sequence to use if one wants to accomplish a Markovnikov addition of water to an alkene with minimal skeletal rearrangement? A) water + dilute acid B) water + concentrated acid C) oxymercuration-demercuration D) hydroboration-oxidation E) none of the above
Answer: C Section: 8.5
What two atomic orbitals or hybrid atomic orbitals overlap to form the CC σ bond in ethylene? A) C sp3 + C sp3 B) C sp3 + C sp2 C) C sp2 + C sp2 D) C sp3 + C p E) C sp2 + C p
Answer: C Section: 7.2
Which of the following best approximates the CCC bond angle of propene? A) 90° B) 109° C) 120° D) 150° E) 180°
Answer: C Section: 7.2
How many elements of unsaturation are implied by the molecular formula C5H8O? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: C Section: 7.3
How many elements of unsaturation are implied by the molecular formula C7H11Cl? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: C Section: 7.3
The prostaglandin precursor arachidonic acid has the molecular formula C20H32O2. Given that arachidonic acid is an acyclic carboxylic acid that contains no carbon-carbon triple bonds, how many carbon-carbon double bonds are present? A) 2 B) 3 C) 4 D) 5 E) 6
Answer: C Section: 7.3
The steroid testosterone has the molecular formula C19H28O2. Given that there are two P -bond in a molecule of testosterone, how many rings are present in each molecule? A) 2 B) 3 C) 4 D) 5 E) 6
Answer: C Section: 7.3
Which of the following molecular formulas corresponds to a monocyclic saturated compound? A) C6H6 B) C3H7Br C) C3H7N D) C3H8O
Answer: C Section: 7.3
Humulene is a monocyclic terpene constituent of carnations. When 0.25 mol of humulene is hydrogenated in the presence of platinum catalyst, 0.75 mol of H2 reacts with the humulene to produce a monocyclic hydrocarbon of formula C15H30. What is the molecular formula of humulene?
Answer: C15H24 Section: 8.10
Draw the alkene of formula C5H10 which evolves the most heat per mole upon hydrogenation.
Answer: CH2CHCH2CH2CH3 Section: 7.7
Give the structure of the alkene which would yield the following products upon ozonolysis-reduction. CH3CH2CH2CH2CHO + CH2O
Answer: CH3CH2CH2CH2CHCH2 Section: 8.15
Which has the higher boiling point, cis- or trans-hex-3-ene? Briefly explain your choice.
Answer: Cis-Hex-3-ene has the higher boiling point since it has a net molecular dipole moment while the trans-isomer does not. The presence of a permanent molecular dipole allows for stronger intermolecular attractions. Section: 7.8
Compare the relative heats of hydrogenation of cyclobutene and cyclopentene and explain the difference in magnitude.
Answer: Cyclobutene's heat of hydrogenation is larger in magnitude than cyclopentene's by about 4 kcal/mol. This is due to additional ring strain introduced into the smaller ring by sp2 centers. Section: 7.7
In the group shown below, which of the following alcohols is (are) likely to yield a product where skeletal rearrangement has occurred when treated with sulfuric acid? 3-methyl-3-pentanol, 3,3-dimethyl-2-butanol, 2,2-dimethylcyclohexanol A) 3-methyl-3-pentanol only B) 3,3-dimethyl-2-butanol only C) 2,2-dimethylcyclohexanol only D) both 3,3-dimethyl-2-butanol and 2,2-dimethylcyclohexanol E) None of these three alcohols is prone to rearrangement.
Answer: D Section: 7.10
Which of the following cycloalkenes would be expected to be stable? A) 1 & 2 B) 2 & 3 C) 2 D) 1 & 3 E) None are stable.
Answer: D Section: 7.7
Dehydrohalogenation of 2-bromobutane in the presence of a strong base proceeds via which of the following mechanistic pathways? A) SN1 B) SN2 C) E1 D) E2 E) none of the above
Answer: D Section: 7.9
Dehydrohalogenation of an alkyl halide by treating it with a strong base to yield an alkene product typically occurs by what reaction mechanism? A) SN1 B) SN2 C) E1 D) E2 E) free radical
Answer: D Section: 7.9
Identify the major product of the reaction below.
Answer: D Section: 7.9
What kind of reactive intermediate is present in the mechanism of the following reaction? A) alkyne B) allylic anion C) allylic cation D) allylic radical E) benzylic cation
Answer: D Section: 7.9
Both (E)- and (Z)-hex-3-ene can be treated with D2 in the presence of a platinum catalyst. How are the products from these two reactions related to each other? A) The (E)- and (Z)-isomers generate the same products but in differing amounts. B) The (E)- and (Z)-isomers generate the same products in exactly the same amounts. C) The products of the two isomers are related as constitutional isomers. D) The products of the two isomers are related as diastereomers. E) The products of the two isomers are related as enantiomers.
Answer: D Section: 8.10
What is the major product of the following reaction?
Answer: D Section: 8.4
Which of the following statements applies to the E2 mechanism? A) It occurs with inversion of stereochemistry. B) It occurs with racemization of stereochemistry. C) It proceeds through the more stable carbocation intermediate. D) The C-H and C-X bonds that break must be anti. E) Use of a bulky base gives the more highly substituted alkene product.
Answer: D Section:7.9
Carbon-carbon single bonds tend to be ________ and ________ than carbon-carbon double bonds. A) shorter, stronger B) longer, stronger C) shorter, weaker D) longer, weaker
Answer: D Section: 7.2
How many elements of unsaturation do molecules with a molecular formula of C8H4N2 have? A) 2 B) 4 C) 6 D) 8 E) 10
Answer: D Section: 7.3
By what mechanism does cyclohexanol react when treated in sulfuric acid and what compound results? A) E1; methoxycyclohexane B) E2; methoxycyclohexane C) SN1; methoxycyclohexane D) E2; cyclohexene E) E1; cyclohexene
Answer: E Section: 7.10
Which of the following alkenes has the largest molar heat of hydrogenation (ie, releases the most heat upon hydrogenation)? A) 2,3-dimethyl-2-butene B) 2-methyl-2-butene C) trans-2-butene D) cis-2-butene E) 1-hexene
Answer: E Section: 7.7
Provide the reagents necessary to complete the following transformation. A) 1. BH3∙THF 2. H2O2, HO- B) H2O, H2SO4 C) OsO4, H2O2 D) CH3CO3H E) 1. CH3CO3H 2. H+, H2O
Answer: E Section: 8.13
Which of the following compounds is (are) appropriate to promote the cationic polymerization of isobutylene? A) H2SO4 B) BF3 C) ROOR D) NaOH E) both H2SO4 and BF3
Answer: E Section: 8.16
Acid catalyzed hydration (H2SO4/water/△) of an unknown compound (A)with a chemical formula C6H12, yielded a racemic mixture of product C6H13OH. Which, if any, of the following compounds is/are possible structures for the initial compound (A)? A) compound 1 only B) compounds 2 and 3 C) compound 2 only D) compounds 1 and 3 E) none of the above
Answer: E Section: 8.4
Treatment of 2-methylpropene with which of the following reaction conditions results in an anti-Markovnikov addition product? A) dry gaseous HBr with peroxides present B) BH3-THF, followed by alkaline H2O2 C) aqueous Hg(OAc)2, followed by alkaline NaBH4 D) dilute H2SO4 and heat E) both A and B
Answer: E Section: 8.7
Which of the following additions to alkenes occur(s) specifically in an syn fashion? A) dihydroxylation using OsO4, H2O2 B) addition of H2 C) hydroboration D) addition of HCl E) A, B, and C
Answer: E Section: 8.14
What two atomic orbitals or hybrid atomic orbitals overlap to form the CC π bond in ethylene? A) C sp3 + C sp3 B) C sp3 + C sp2 C) C sp2 + C sp2 D) C sp2 + C p E) C p + C p
Answer: E Section: 7.2
How many elements of unsaturation are implied by the molecular formula C5H5NO2? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: E Section: 7.3
How many elements of unsaturation are implied by the molecular formula C8H11N? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: E Section: 7.3
Ozonolysis-reduction of an unknown alkene gives equal amounts of CH3CH2CHO and CH3CH2CH2CHO. Name the unknown alkene.
Answer: Either (E)- or (Z)-3-heptene Section: 8.15
Provide the structure of the monomer from which PVC or poly(vinyl chloride) is made.
Answer: H2CCHCl Section: 7.6
Does the alkene shown below violate Bredt's rule?
Answer: No Diff: 2 Section: 7.7
Does the alkene shown below violate Bredt's rule?
Answer: No Section: 7.7
The following reaction is known to proceed by a free radical chain mechanism. Suggest a reasonable, step-by-step mechanism for this reaction. CH3CHCH2 + CHCl3 CH3CH2CH2CCl3
Answer: ROOR → 2 RO∙ RO∙ + HCCl3 → ROH + ∙CCl3 Cl3C∙ + CH2CHCH3 → Cl3CCH2CH3 Cl3CCH2CH3 + HCCl3 → Cl3CCH2CH2CH3 + ∙CCl3 Section: 8.3
Why is rotation about the carbon-carbon double bond in alkenes prohibited while relatively free rotation can occur about the carbon-carbon single bond in alkanes?
Answer: Rotation about the CC single bond in alkanes can occur without breaking the bond or disrupting the orbital overlap. For rotation to occur about a CC, the π bond would have to be broken since the p orbital overlap from which the bond is formed is disrupted by rotation. Section: 7.2
Why can methyl acrylate (H2CCHCO2CH3) be polymerized through anionic polymerization?
Answer: The intermediate carbanion and the transition state leading to it are stabilized by the electron-withdrawing capacity of the carbonyl group. Section: 8.16
Based on the relative stabilities of the intermediates involved, explain the basis for Markovinkov's rule in the addition of hydrogen halides to alkenes.
Answer: The rate-determining step in this reaction is the production of a carbocation intermediate. Since this step is endothermic, Hammond's postulate allows one to gauge the relative stabilities of the transition states by comparing the relative stabilities of the carbocation intermediates. The reaction pathway which produces the more substituted carbocation will thus occur more rapidly. Section: 8.3
Explain the regioselectivity observed in the radical addition of HBr to 2-methylpropene.
Answer: The reaction proceeds via the addition of Br∙ to the alkene. Two competing pathways are possible, but the transition state leading to the more substituted alkyl radical is lower in energy. This process ultimately makes the addition anti-Markovnikov in nature. Section: 8.3
Which base, ammonia (NH3) or triethylamine [(CH3CH2)3N], would be a better choice for use in converting 1-chlorohexane to hex-1-ene? Explain briefly.
Answer: Triethylamine. Amines can serve as both nucleophiles and as bases in reactions with alkyl halides. Increasing the steric bulk about the nitrogen diminishes the nucleophilicity while allowing the amine to continue to function effectively as a base. Section: 7.9
Does the alkene shown below violate Bredt's rule?
Answer: Yes Section: 7.7
What reagent could be used to prepare cyclopentene from trans-1,2-dibromocyclopentane?
Answer: Zn/CH3CO2H Section: 7.9
What cyclic products results when 1,8-nonadiene is treated with Grubbs catalyst?
Answer: cycloheptene Section: 8.17
Provide the proper IUPAC name for the alkene shown below.
Answer: cyclopentene Section: 7.4
Provide the proper IUPAC name for the alkene shown below. CH2CHCH2CH2CH2CH3
Answer: hex-1-ene Section:7.4
The mechanism for the acid-catalyzed hydration of alkenes is simply the reverse of the mechanism by which alcohols are dehydrated using concentrated acid. This is an illustration of the principle of ________.
Answer: microscopic reversibility Section: 8.4
Name the compound PhCO3H and give its most common use as a reagent.
Answer: peroxybenzoic acid; an oxidizing agent which converts alkenes to epoxides Section: 8.12
How many distinct terminal alkynes exist with a molecular formula of C5H8? A) 1 B) 2 C) 3 D) 4 E) 5
B) 2
In trans-hept-4-en-2-yne the shortest carbon-carbon bond is between carbons __________. A) 1 and 2 B) 2 and 3 C) 3 and 4 D) 4 and 5 E) 6 and 7
B) 2 and 3
Which of the following bases are sufficiently strong to deprotonate a terminal alkyne with an equilibrium constant greater than 1? 1) sodium methoxide 2) lithium diisopropyl amide 3) n-butyl lithium 4) phenylmagnesium bromide A) 1, 2, and 3 B) 2, 3 and 4 C) 2 and 3 D) 3 and 4 E) 1, 2, 3 and 4
B) 2, 3 and 4
Which of the species below is less basic than acetylide? A) CH3Li B) CH3ONa C) CH3MgBr D) both A and C E) all of the above
B) CH3ONa
Which of the following reagents should be used to convert hex-3-yne to (E)-hex-3-ene? A) H2, Pt B) Na, NH3 C) H2, Lindlar's catalyst D) H2SO4, H2O E) HgSO4, H2O
B) Na, NH3
What class of organic product results when 1-heptyne is treated with a mixture of mercuric acetate in aqueous sulfuric acid? A) aldehyde B) ketone C) diol D) ether E) carboxylic acid
B) ketone
In the addition of hydrogen bromide to alkynes in the absence of peroxides, which of the following species is thought to be an intermediate? A) vinyl anion B) vinyl cation C) vinyl radical D) carbene E) none of the above
B) vinyl cation
Among the compounds water, but-1-yne, but-2-yne, and ethane, which are stronger acids than ammonia? A) but-1-yne and ethane B) water and but-1-yne C) water and ethane D) but-1-yne and but-2-yne
B) water and but-1-yne
What is the major organic product that results when 3-heptyne is hydrogenated in the presence of Lindlar's catalyst? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane
C) (Z)-3-heptene
How many distinct alkynes exist with a molecular formula of C4H6? A) 0 B) 1 C) 2 D) 3 E) 4
C) 2
How many distinct internal alkynes exist with a molecular formula of C6H10? A) 1 B) 2 C) 3 D) 4 E) 5
C) 3
Which of the following reagents should be used to convert hex-3-yne to (Z)-hex-3-ene? A) H2, Pt B) Na, NH3 C) H2, Lindlar's catalyst D) H2SO4, H2O E) HgSO4, H2O
C) H2, Lindlar's catalyst
What is the major organic product that results when 3-heptyne is treated with sodium metal in ammonia? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane
D) (E)-3-heptene
Which of the follwing reagents will convert 1 mole of 3-methylpent-1-yne into 3-methylpentane? A) 1 mole of Br2 in CCl4 B) 2 moles of Cl2 in CCl4 C) 2 moles of HCl D) 2 moles H2, Ni and heat E) 1 mole H2, Ni and heat
D) 2 moles H2, Ni and heat
What is the major organic product that results when 1-heptyne is treated with 2 equivalents of HBr? A) 2,3-dibromo-1-heptene B) 2,3-dibromo-2-heptene C) 1,2-dibromoheptane D) 2,2-dibromoheptane E) 1,1-dibromoheptane
D) 2,2-dibromoheptane
How many moles of oxygen are required in the complete combustion of 1 mole of acetylene? A) 1 B) 1.5 C) 2 D) 2.5 E) 3
D) 2.5
is produced when 1 equivalent of HBr is added to hex-1-yne in the presence of peroxides. A) 2-Bromohex-1-ene B) E-1-Bromohex-1-ene C) Z-1-Bromohex-1-ene D) A mixture of E and Z isomers of 1-bromohex-1-ene E) E-2-Bromohex-2-ene
D) A mixture of E and Z isomers of 1-bromohex-1-ene
Which of the alkyne addition reactions below involve(s) an enol intermediate? A) hydroboration/oxidation B) treatment with HgSO4 in dilute H2SO4 C) hydrogenation D) both A and B E) none of the above
D) both A and B
When 2,2-dibromobutane is heated at 200°C in the presence of molten KOH, what is the major organic product? A) 1-bromobut-1-yne B) 1-bromobut-2-yne C) but-1-yne D) but-2-yne E) but-1-ene
D) but-2-yne
Which of the following improperly describes the physical properties of an alkyne? A) relatively nonpolar B) nearly insoluble in water C) less dense than water D) insoluble in most organic solvents E) boiling point nearly the same as an alkane with similar carbon skeleton
D) insoluble in most organic solvents
The carbon-carbon triple bond of an alkyne is composed of __________. A) three σ bonds B) three π bonds C) two σ bonds and one π bond D) one σ bond and two π bonds
D) one σ bond and two π bonds
In the reduction of alkynes using sodium in liquid ammonia, which of the species below is not thought to be an intermediate in the commonly accepted mechanism? A) vinyl anion B) vinyl radical C) radical anion D) vinyl cation
D) vinyl cation
What is the major organic product that results when 3-heptyne is subjected to excess hydrogen and a platinum catalyst? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane
E) heptane
60) Which of the following describes an unsymmetrical addition reaction? A) propyne with 1 mole H2, Ni and heat B) propyne with 2 moles Cl2 in CCl4 C) propyne with 1 mole Br2 in CCl4 D) propyne with Na/NH3 E) propyne with 1 mole HBr
E) propyne with 1 mole HBr
Draw all likely alkene products in the following reaction and circle the product you expect to predominate.
No alkene product likely. Section: 7.7
Draw all likely products of the following reaction and circle the product you expect to predominate.
Section: 7.10
Draw all likely products of the following reaction and circle the product you expect to predominate. CH3CH(OH)CH2CH2CH3
Section: 7.10
Draw the major product of the following reaction.
Section: 7.10
Propose a detailed, step-by-step mechanism for the reaction pathway shown below.
Section: 7.10
Provide the major organic product in the reaction shown below.
Section: 7.10
Circle all atoms that are coplanar in the molecule below.
Section: 7.2
Draw an acceptable structure for 1,2-dimethylcyclohexene.
Section: 7.4
Draw an acceptable structure for 4-ethylhept-1-ene.
Section: 7.4
Draw an acceptable structure for 4-phenylbut-1-ene.
Section: 7.4
Draw and name all alkenes which have the molecular formula C4H8.
Section: 7.4
Draw and name the six alkenes which have the molecular formula C5H10.
Section: 7.4
Draw an acceptable structure for (Z)-2-chloro-4-ethylhex-2-ene.
Section: 7.5
Provide a structure for (Z)-4-bromo-3-heptene.
Section: 7.5
Provide the structure of (Z)-1-chloro-1-fluoro-1-butene.
Section: 7.5
Translate the following condensed structure to a line-angle structure. (E) CH3CBrCH(CH2)2C(O)CH(CH3)2
Section: 7.5
Circle the alkene below which has the smallest heat of hydrogenation.
Section: 7.7
Circle the alkene isomer that has the largest heat of hydrogenation
Section: 7.7
Circle the most stable alkene in the set of isomers below.
Section: 7.7
There are three isomeric methylbutene structures. Draw each of them and then circle the isomer with the highest heat of hydrogenation.
Section: 7.7
Draw all likely alkene products in the following reaction and circle the product you expect to predominate.
Section: 7.9
Draw the alkene product which results when 1-bromopentane is heated in acetone containing NaOH. Give a detailed, step-by-step mechanism for the production of this compound.
Section: 7.9
Provide the major organic product in the reaction shown below
Section: 7.9
Provide the major organic product in the reaction shown below.
Section: 7.9
Provide the structure of the major organic product of the reaction below.
Section: 7.9
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.10
Draw the major organic product(s) generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.10
Complete the following reaction by filling in the necessary reagents.
Section: 8.11
Draw the Lewis structure of dibromocarbene.
Section: 8.11
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.11
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.12
Draw the major organic product(s) generated in the reaction below. Pay particular attention to regio- and stereochemical detail
Section: 8.12
Provide the major organic product of the reaction below.
Section: 8.12
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.13
Provide a detailed, step-by-step mechanism for the reaction shown below.
Section: 8.13
Provide the major organic product of the reaction below.
Section: 8.13
Provide the structure of the major organic product of the reaction below.
Section: 8.13
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.14
Draw the major organic product(s) generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.14
Provide the major organic product of the following reaction.
Section: 8.14
Provide the major organic product of the reaction below.
Section: 8.14
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.15
Predict the structure of the products resulting from the reaction between limonene, a natural terpene found in citrus fruit, and ozone, followed by work up with dimethyl sulfide.
Section: 8.15
Provide the major organic product of the following reaction.
Section: 8.15
Consider how the ICl bond is polarized and predict the product which results when this mixed halogen adds to 1-methylcyclohexene.
Section: 8.8
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail
Section: 8.8
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.8
Draw the major organic product(s) generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.8
Provide a detailed, step-by-step mechanism for the reaction shown below.
Section: 8.8
Provide the major organic product of the reaction below
Section: 8.8
Complete the following reaction by providing a structure of the expected product. Be sure to indicate all relevant stereochemistry
Section: 8.9
Draw the major organic product generated in the reaction below. Pay particular attention to regio- and stereochemical detail.
Section: 8.9
Predict the product of the following reaction. Include any relevant stereochemistry.
Section: 8.9
Provide the structure of the major organic product of the reaction below
Section: 8.9
Describe the major products of the following reaction and predict which of the products would predominate. Explain and defend your answer.
The Hofmann product would most likely predominate due to the coplanar cis configuration of the Br and H across the bridge. The E2 mechanism favors anti alignment of the H with the halogen leaving group. There are two possible anti-aligned H atoms that would lead to the Hofmann product. Section: 7.9
Describe the major elimination products of the following reaction, including any stereochemistry, and indicate which structure will predominate. Explain and defend your answer
This reaction would be predicted to follow an E2 anti-elimination in the formation of 2 - Zaitzef products (E and Z) and the 1 Hofmann product. The predicted predominating species would be the Zaitzef (E) structure because E2 favors anti alignment of the beta-H and the halogen. When considering 2 -beta H atoms in an E2 elimination, the best alignment would be achieved when the starting material assumes a conformation where the methyl and phenyl groups are aligned anti with respect to each other in a Newman projection. Section: 7.9
