Question 1

Describe a sequence of reactions by which the compound shown below can be straightforwardly prepared from acetylene.

Accepted Answer

1. NaNH₂ 2.

Question 2

Which of the alkyne addition reactions below involve(s) an enol intermediate?

Accepted Answer

A)  hydroboration/oxidation 
B)  treatment with HgSO4 in dilute H2SO4 
C)  hydrogenation 
D)  both A and B 
E)  none of the above 
A)  hydroboration/oxidation 
B)  treatment with HgSO4 in dilute H2SO4 
C)  hydrogenation 
D)  both A and B 
E)  none of the above

Question 3

Draw the products which result when oct-3-yne is heated in basic potassium permanganate solution.

Accepted Answer

CH₃CH₂CO₂^-K⁺ +

Question 4

What two organic compounds result when 3-heptyne is treated with ozone followed by hydrolysis?

Accepted Answer

CH₃CH₂CO₂H an

Question 5

Provide the major organic product of the reaction shown below.

Accepted Answer

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

Question 6

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

Accepted Answer

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

Question 7

Which of the following reagents will convert 1 mole of 3-methylpent-1-yne into 3-methylpentane?

Accepted Answer

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 
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

Question 8

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

Accepted Answer

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

Question 9

Describe a sequence of reactions by which (Z)-hex-3-en-1-ol can be straightforwardly prepared from but-1-yne.

Accepted Answer

1. NaNH₂ 2. ethylene

Question 10

Describe a sequence of reactions by which CH3CH2CH2COCH2CH3 can be straightforwardly prepared from but-1-yne.

Accepted Answer

1. NaNH₂ 2.

Question 11

Which of the following describes an unsymmetrical addition reaction?

Accepted Answer

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 
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

Question 12

Complete the synthesis below by providing all necessary reagents and show all intermediate structures.

Accepted Answer

1) NaNH₂, 2

Question 13

What is the major organic product that results when 3-heptyne is hydrogenated in the presence of Lindlar's catalyst?

Accepted Answer

A)  2-heptyne 
B)  (Z)-2-heptene 
C)  (Z)-3-heptene 
D)  (
E) -3-heptene 
E)  heptane 
A)  2-heptyne 
B)  (Z)-2-heptene 
C)  (Z)-3-heptene 
D)  (
E) -3-heptene 
E)  heptane

Question 14

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

Accepted Answer

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

Question 15

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

Accepted Answer

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

Question 16

Complete the short synthesis below by providing the necessary reagents.

Accepted Answer

1) Br<sub>2</sub> 
2

Question 17

Predict the necessary starting material for the reaction below.

Accepted Answer

3-methyl-2

Question 18

Name the product which results when CH3C=CLi reacts with CH3CH2COCH2CH3 followed by addition of water.

Accepted Answer

3-ethylhex

Question 19

Provide the IUPAC name for the compound below.

Accepted Answer

3-ethylhex

Question 20

Why is a terminal alkyne favored when sodium amide (NaNH2) is used in an elimination reaction with 2,3-dichlorohexane?

Accepted Answer

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. 
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.

Exam 9: Alkynes

Describe a sequence of reactions by which the compound shown below can be straightforwardly prepared from acetylene.

Which of the alkyne addition reactions below involve(s) an enol intermediate?

Draw the products which result when oct-3-yne is heated in basic potassium permanganate solution.

What two organic compounds result when 3-heptyne is treated with ozone followed by hydrolysis?

Provide the major organic product of the reaction shown below.

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

Which of the following reagents will convert 1 mole of 3-methylpent-1-yne into 3-methylpentane?

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

Describe a sequence of reactions by which (Z)-hex-3-en-1-ol can be straightforwardly prepared from but-1-yne.

Describe a sequence of reactions by which CH3CH2CH2COCH2CH3 can be straightforwardly prepared from but-1-yne.

Which of the following describes an unsymmetrical addition reaction?

Complete the synthesis below by providing all necessary reagents and show all intermediate structures.

What is the major organic product that results when 3-heptyne is hydrogenated in the presence of Lindlar's catalyst?

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

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

Complete the short synthesis below by providing the necessary reagents.

Predict the necessary starting material for the reaction below.

Name the product which results when CH3C=CLi reacts with CH3CH2COCH2CH3 followed by addition of water.

Provide the IUPAC name for the compound below.

Why is a terminal alkyne favored when sodium amide (NaNH2) is used in an elimination reaction with 2,3-dichlorohexane?

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

Describe a sequence of reactions by which CH₃CH₂CH₂COCH₂CH₃ can be straightforwardly prepared from but-1-yne.

Name the product which results when CH₃C=CLi reacts with CH₃CH₂COCH₂CH₃ followed by addition of water.

Why is a terminal alkyne favored when sodium amide (NaNH₂) is used in an elimination reaction with 2,3-dichlorohexane?