Question 1

Which of the following is the most stable conformation of trans-1-ethyl-3-methylcyclohexane?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)    D

Question 2

Which of the following is the most stable conformation of cis-1-isopropyl-3-methylcyclohexane?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)    C

Question 3

Which of the following statements is not true regarding the conformation of substituted cyclohexanes?

Accepted Answer

A) ring flip of substituted cyclohexanes flips the axial and equatorial positions of substituents 
B) substituted cyclohexanes are destabilized by 1,3-diaxial interactions 
C) the twist-boat conformation of cyclohexane is more stable than the chair conformation 
D) the relative amount of two conformations of substituted cyclohexanes can be determined from the difference in strain energy 
A) ring flip of substituted cyclohexanes flips the axial and equatorial positions of substituents 
B) substituted cyclohexanes are destabilized by 1,3-diaxial interactions 
C) the twist-boat conformation of cyclohexane is more stable than the chair conformation 
D) the relative amount of two conformations of substituted cyclohexanes can be determined from the difference in strain energy C

Question 4

Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?

Accepted Answer

A) 1,1-dimethylcyclohexane 
B) cis-1,2-dimethylcyclohexane 
C) trans-1,2-dimethylcyclohexane 
D) trans-1,3-dimethylcyclohexane 
A) 1,1-dimethylcyclohexane 
B) cis-1,2-dimethylcyclohexane 
C) trans-1,2-dimethylcyclohexane 
D) trans-1,3-dimethylcyclohexane

Question 5

In cycloheptane,which of the following factors contributes the least to the stability of the ring conformation?

Accepted Answer

A) torsional strain 
B) angle strain 
C) steric strain 
D) all of these contribute to an approximately equal degree 
A) torsional strain 
B) angle strain 
C) steric strain 
D) all of these contribute to an approximately equal degree

Question 6

Which of the following cycloalkanes would be the most similar to its open chain counterpart?

Accepted Answer

A) cyclodecane 
B) cyclooctane 
C) cyclopentane 
D) cyclopropane 
A) cyclodecane 
B) cyclooctane 
C) cyclopentane 
D) cyclopropane

Question 7

Which one of the following structures represents a different compound from the other three?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 8

Instructions: (-)-Menthol is responsible for the characteristic flavor and taste of peppermint.The structure of (-)-menthol is shown below.Use this information to answer the following question.

-Refer to instructions.On the chair template provided below,draw the two chair conformations that are in equilibrium for (-)-menthol.

Accepted Answer

The answer of Instructions: (-)-Menthol is responsible for the characteristic...

Question 9

D-Pinitol is an interesting hexahydroxycyclohexane,whose structure is shown below.  
On the templates provided,draw the two chair conformations that are in equilibrium for D-pinitol.Circle the most stable conformation.

Accepted Answer

The answer of D-Pinitol is an interesting hexahydroxycyclohexane,whose structure is...

Question 10

If the 1,3-diaxial strain for an ethyl group is 4.0 kJ/mol,what is the energy difference between the axial and equatorial conformations of ethylcyclohexane?

Accepted Answer

A) 2.0 kJ/mol 
B) 4.0 kJ/mol 
C) 8.0 kJ/mol 
D) 16.0 kJ/mol 
E) Cannot be determined from the 1,3-diaxial strain 
A) 2.0 kJ/mol 
B) 4.0 kJ/mol 
C) 8.0 kJ/mol 
D) 16.0 kJ/mol 
E) Cannot be determined from the 1,3-diaxial strain

Question 11

In which of the following compounds would the carbon-carbon bond angle diverge the greatest from 109$\circ$?

Accepted Answer

A) cyclodecane 
B) cyclooctane 
C) cyclopentane 
D) cyclopropane 
A) cyclodecane 
B) cyclooctane 
C) cyclopentane 
D) cyclopropane

Question 12

Which one of the following structures represents a different compound from the other three?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 13

Which of the following structures represents trans-1,3-dimethylcyclohexane?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 14

Which of the following cycloalkanes has the most ring strain?

Accepted Answer

A) cyclopropane 
B) cyclobutane 
C) cyclopentane 
D) cyclohexane 
A) cyclopropane 
B) cyclobutane 
C) cyclopentane 
D) cyclohexane

Question 15

Which of the following structures represents trans-1,2-dimethylcyclohexane?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 16

Substitution of which of the following groups on a cycloalkane would result in the greatest amount of steric strain?

Accepted Answer

A) bromo 
B) ethyl 
C) isopropyl 
D) hydroxyl 
A) bromo 
B) ethyl 
C) isopropyl 
D) hydroxyl

Question 17

If cyclohexane were planar,how much torsional strain would be present in the planar molecule? Assume that the energy cost for each H«H eclipsing interaction is 4.0 kcal/mol.

Accepted Answer

A) 12.0 kJ/mol 
B) 24.0 kJ/mol 
C) 36.0 kJ/mol 
D) 48.0 kJ/mol 
E) 64.0 kJ/mol 
A) 12.0 kJ/mol 
B) 24.0 kJ/mol 
C) 36.0 kJ/mol 
D) 48.0 kJ/mol 
E) 64.0 kJ/mol

Question 18

What is the energy difference between the two chair conformations of the following compound that is due to steric strain?
Cis-1-bromo-4-isopropylcyclohexane

Accepted Answer

A) 7.2 kJ/mol 
B) 5.6 kJ/mol 
C) 9.2 kJ/mol 
D) 11.2 kJ/mol 
A) 7.2 kJ/mol 
B) 5.6 kJ/mol 
C) 9.2 kJ/mol 
D) 11.2 kJ/mol

Exam 4: Organic Compounds: Cycloalkanes and Their Stereochemistry

Which of the following is the most stable conformation of trans-1-ethyl-3-methylcyclohexane?

Which of the following is the most stable conformation of cis-1-isopropyl-3-methylcyclohexane?

Which of the following statements is not true regarding the conformation of substituted cyclohexanes?

Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?

In cycloheptane,which of the following factors contributes the least to the stability of the ring conformation?

Which of the following cycloalkanes would be the most similar to its open chain counterpart?

Which one of the following structures represents a different compound from the other three?

D-Pinitol is an interesting hexahydroxycyclohexane,whose structure is shown below. On the templates provided,draw the two chair conformations that are in equilibrium for D-pinitol.Circle the most stable conformation.

If the 1,3-diaxial strain for an ethyl group is 4.0 kJ/mol,what is the energy difference between the axial and equatorial conformations of ethylcyclohexane?

In which of the following compounds would the carbon-carbon bond angle diverge the greatest from 109 ∘\circ∘ ?

Which one of the following structures represents a different compound from the other three?

Which of the following structures represents trans-1,3-dimethylcyclohexane?

Which of the following cycloalkanes has the most ring strain?

Which of the following structures represents trans-1,2-dimethylcyclohexane?

Substitution of which of the following groups on a cycloalkane would result in the greatest amount of steric strain?

If cyclohexane were planar,how much torsional strain would be present in the planar molecule? Assume that the energy cost for each H«H eclipsing interaction is 4.0 kcal/mol.

What is the energy difference between the two chair conformations of the following compound that is due to steric strain? Cis-1-bromo-4-isopropylcyclohexane

Structure and Bonding

Polar Covalent Bonds: Acids and Bases

Organic Compounds: Alkanes and Their Stereochemistry

Stereochemistry at Tetrahedral Centers

An Overview of Organic Reactions

Alkenes and Alkynes

Reactions of Alkenes and Alkynes

Aromatic Compounds

Structure Determination: Mass Spectrometry,infrared Spectroscopy,and Ultraviolet Spectroscopy

Structure Determination: Nuclear Magnetic Resonance Spectroscopy

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols,phenols,and Thiols: Ethers and Sulfides

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Nitriles

Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution and Condensation Reactions

Amines and Heterocycles

Biomolecules: Amino Acids,peptides,and Proteins

Amino Acid Metabolism

Biomolecules: Carbohydrates

Carbohydrate Metabolism

Biomolecules: Lipids and Their Metabolism

Biomolecules: Nucleic Acids and Their Metabolism

Filters

In which of the following compounds would the carbon-carbon bond angle diverge the greatest from 109^$\circ$?