Question 1

Describe a sequence of reactions by which hept-3-yne can be straightforwardly prepared from acetylene.

Accepted Answer

1. NaNH₂ 2.

Question 2

Provide the structure of the major organic product(s) in the reaction sequence below.

Accepted Answer

The answer of Provide the structure of the major organic...

Question 3

Which of the species below is less basic than acetylide?

Accepted Answer

A)  CH3Li 
B)  CH3ONa 
C)  CH3MgBr 
D)  both A and C 
E)  all of the above 
A)  CH3Li 
B)  CH3ONa 
C)  CH3MgBr 
D)  both A and C 
E)  all of the above

Question 4

Describe a sequence of reactions by which butylbenzene can be straightforwardly prepared from phenylacetylene.

Accepted Answer

1. NaNH₂ 2.

Question 5

Give the IUPAC name for HC=CCH2CH2CH3.

Accepted Answer

The answer of Give the IUPAC name for HC=CCH2CH2CH3....

Question 6

Which of the following reagents should be used to convert hex-3-yne to (Z)-hex-3-ene?

Accepted Answer

A)  H2, Pt 
B)  Na, NH3 
C)  H2, Lindlar's catalyst 
D)  H2SO4, H2O 
E)  HgSO4, H2O 
A)  H2, Pt 
B)  Na, NH3 
C)  H2, Lindlar's catalyst 
D)  H2SO4, H2O 
E)  HgSO4, H2O

Question 7

Describe a sequence of reactions by which 1-propylcyclohexan-1-ol can be straightforwardly prepared from propyne.

Accepted Answer

1. NaNH₂ 2.

Question 8

How many distinct alkynes exist with a molecular formula of C4H8?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  4 
A)  0 
B)  1 
C)  2 
D)  3 
E)  4

Question 9

Provide a correct structure for the product of the following reaction.

Accepted Answer

The answer of Provide a correct structure for the product...

Question 10

What is the pKa of a terminal alkyne?

Accepted Answer

A)  4 
B)  10 
C)  16 
D)  25 
E)  44 
A)  4 
B)  10 
C)  16 
D)  25 
E)  44

Question 11

What major organic product results when 3-octyne is treated with sodium metal in liquid ammonia?

Accepted Answer

A)  (
E) -3-octene 
B)  (Z)-3-octene 
C)  1-octyne 
D)  1-octene 
E)  octane 
A)  (
E) -3-octene 
B)  (Z)-3-octene 
C)  1-octyne 
D)  1-octene 
E)  octane

Question 12

Draw an acceptable structure for acetylene.

Accepted Answer

The answer of Draw an acceptable structure for acetylene....

Question 13

Describe a sequence of reactions by which meso-hexane-3,4-diol can be straightforwardly prepared from hex-3-yne.

Accepted Answer

1. H₂, Lindlar's catalyst 2.

Question 14

What class of organic product results when 1-heptyne is reacted with disiamylborane followed by treatment with basic hydrogen peroxide?

Accepted Answer

A)  aldehyde 
B)  ketone 
C)  diol 
D)  ether 
E)  carboxylic acid 
A)  aldehyde 
B)  ketone 
C)  diol 
D)  ether 
E)  carboxylic acid

Question 15

Provide the major organic product of the reaction shown below.

Accepted Answer

The answer of Provide the major organic product of the...

Question 16

2-Methylhex-3-yne can be prepared by the reaction of an alkynide with an alkyl halide. Does the better synthesis involve alkynide attack on bromoethane or on 2-bromopropane? Explain your reasoning.

Accepted Answer

Attack on the primary bromide

Question 17

Describe a sequence of reactions by which (E)-5-bromopent-2-ene can be straightforwardly prepared from propyne.

Accepted Answer

1. NaNH₂ 2. ethylene

Question 18

Which of the following $\underline{\text{ improperly  }}$ describes the physical properties of an alkyne?

Accepted Answer

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 
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

Question 19

Among the compounds water, but-1-yne, but-2-yne, and ethane, which are stronger acids than ammonia?

Accepted Answer

A)  but-1-yne and ethane 
B)  water and but-1-yne 
C)  water and ethane 
D)  but-1-yne and but-2-yne 
A)  but-1-yne and ethane 
B)  water and but-1-yne 
C)  water and ethane 
D)  but-1-yne and but-2-yne

Question 20

Provide the IUPAC name for (CH3)2CHCH2CH(OH)CH2C≡CCH3.

Accepted Answer

2-methyl-6

Exam 9: Alkynes

Describe a sequence of reactions by which hept-3-yne can be straightforwardly prepared from acetylene.

Provide the structure of the major organic product(s) in the reaction sequence below.

Which of the species below is less basic than acetylide?

Describe a sequence of reactions by which butylbenzene can be straightforwardly prepared from phenylacetylene.

Give the IUPAC name for HC=CCH2CH2CH3.

Which of the following reagents should be used to convert hex-3-yne to (Z)-hex-3-ene?

Describe a sequence of reactions by which 1-propylcyclohexan-1-ol can be straightforwardly prepared from propyne.

How many distinct alkynes exist with a molecular formula of C4H8?

Provide a correct structure for the product of the following reaction.

What is the pKa of a terminal alkyne?

What major organic product results when 3-octyne is treated with sodium metal in liquid ammonia?

Draw an acceptable structure for acetylene.

Describe a sequence of reactions by which meso-hexane-3,4-diol can be straightforwardly prepared from hex-3-yne.

What class of organic product results when 1-heptyne is reacted with disiamylborane followed by treatment with basic hydrogen peroxide?

Provide the major organic product of the reaction shown below.

2-Methylhex-3-yne can be prepared by the reaction of an alkynide with an alkyl halide. Does the better synthesis involve alkynide attack on bromoethane or on 2-bromopropane? Explain your reasoning.

Describe a sequence of reactions by which (E)-5-bromopent-2-ene can be straightforwardly prepared from propyne.

Which of the following improperly ‾\underline{\text{ improperly }} improperly ​ describes the physical properties of an alkyne?

Among the compounds water, but-1-yne, but-2-yne, and ethane, which are stronger acids than ammonia?

Provide the IUPAC name for (CH3)2CHCH2CH(OH)CH2C≡CCH3.

Introduction and Review

Structure and Properties of Organic Molecules

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides: Nucleophilic Substitution and Elimination

Structure and Synthesis of Alkenes

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Give the IUPAC name for HC=CCH₂CH₂CH₃.

How many distinct alkynes exist with a molecular formula of C₄H₈?

Which of the following $\underline{\text{ improperly }}$ describes the physical properties of an alkyne?

Provide the IUPAC name for (CH₃)₂CHCH₂CH(OH)CH₂C≡CCH₃.