
Concept explainers
(a)
Interpretation:
An
Concept introduction:
E2 stands for bimolecular elimination. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
Since the alkyl halide and base influence the

Answer to Problem 13.35P
An alkyl halide that could have been used to synthesize the known alkene exclusively via an E2 reaction paying attention to stereochemistry is:
Explanation of Solution
The structure of the desired alkene is:
The given alkene has both the higher priority groups attached on the opposite side of the double bond. Hence, the stereochemistry is E. Alkenes can be prepared from corresponding alkyl halides via E2 reactions. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion. Thus, the original alkyl halide that could have been used to prepare the given alkene must be:
To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
(b)
Interpretation:
An alkyl halide, that can be used to synthesize the given alkene exclusively via an E2 reaction paying attention to stereochemistry, is to be provided.
Concept introduction:
The name E2 represents bimolecular elimination. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
Since the alkyl halide and base influence the rate of reaction, this is a bimolecular reaction. A strong base is used to form the most substituted alkene as the major product.

Answer to Problem 13.35P
An alkyl halide that could have been used to prepare the given alkene exclusively via an E2 reaction paying attention to stereochemistry is:
Explanation of Solution
The structure of the required alkene is:
The given alkene has both the most priority groups attached on the same side of the double bond. Therefore, the stereochemistry about the double bond is Z. Alkenes can be prepared from corresponding alkyl halides via E2 reactions. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion. Thus, the original alkyl halide that could have been used to prepare the given alkene must be:
To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
(c)
Interpretation:
An alkyl halide, that can be used to synthesize the given alkene exclusively via an E2 reaction paying attention to stereochemistry, is to be provided.
Concept introduction:
The name E2 represents bimolecular elimination. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
Since the alkyl halide and base influence the rate of reaction, this is a bimolecular reaction. A strong base is used to form the most substituted alkene as the major product.

Answer to Problem 13.35P
An alkyl halide that could have been used to prepare the given alkene exclusively via an E2 reaction paying attention to stereochemistry is:
Explanation of Solution
The structure of the desired alkene is:
The alkene is a cycloalkene having two methyl groups attached to the double-bonded carbon atoms. As the carbon atoms in alkenes are
To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
(d)
Interpretation:
An alkyl halide, that can be used to synthesize the given alkene exclusively via an E2 reaction paying attention to stereochemistry, is to be provided.
Concept introduction:
The name E2 represents bimolecular elimination. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
Since the alkyl halide and base influence the rate of reaction, this is a bimolecular reaction. A strong base is used to form the most substituted alkene as the major product.

Answer to Problem 13.35P
An alkyl halide that could have been used to prepare the given alkene exclusively via an E2 reaction paying attention to stereochemistry is:
Explanation of Solution
The structure of the desired alkene is:
The alkene is cyclohexene having three methyl groups as substituents.
As the carbon atoms in alkenes are sp2 hybridized, all the atoms that are directly attached to the double-bonded carbon atoms must be in the plane. There are two chiral centers in the molecule at C3 and C6 carbon atoms. The stereochemistry for those two chiral centers will not change and will be retained as the reaction does not occur at those two chiral centers. Alkenes can be prepared from corresponding alkyl halides via E2 reactions.
This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion. Thus, the original alkyl halide that could have been used to prepare the given alkene must be:
To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
(e)
Interpretation:
An alkyl halide, that can be used to synthesize the given alkene exclusively via an E2 reaction paying attention to stereochemistry, is to be provided.
Concept introduction:
The name E2 represents bimolecular elimination. This reaction is a one-step concerted mechanism. In this step, the C-X and C-H bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
Since the alkyl halide and base influence the rate of reaction, this is a bimolecular reaction. A strong base is used to form the most substituted alkene as the major product.

Answer to Problem 13.35P
An alkyl halide that could have been used to prepare the given alkene exclusively via an E2 reaction paying attention to stereochemistry is:
Explanation of Solution
The structure of the desired alkene is:
The alkene is cyclohexene having three methyl groups as substituents.
As the carbon atoms in alkenes are sp2 hybridized, all the atoms that are directly attached to the double-bonded carbon atoms must be in the plane. There are two chiral centers in the molecule at C3 and C6 carbon atoms. The stereochemistry for those two chiral centers will not change and will be retained as the reaction does not occur at those two chiral centers. Alkenes can be prepared from corresponding alkyl halides via E2 reactions.
This reaction involves a one-step mechanism (concerted) in which carbon-halogen bond and carbon-hydrogen bond breaks to form a double bond. The leaving group and the adjacent hydrogen atom must be anticoplanar in the precursor for the E2 step to be favored. To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion. Thus, the original alkyl halide that could have been used to synthesize the given alkene must be:
To arrive back at the alkyl halide, one must add hydrogen and a halogen on the alkene carbons in an anti-fashion.
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Chapter 13 Solutions
Organic Chemistry: Principles And Mechanisms: Study Guide/solutions Manual (second)
- Calculate the pH and the pOH of each of the following solutions at 25 °C for which the substances ionize completely: (a) 0.000259 M HClO4arrow_forwardWhat is the pH of a 1.0 L buffer made with 0.300 mol of HF (Ka = 6.8 × 10⁻⁴) and 0.200 mol of NaF to which 0.160 mol of NaOH were added?arrow_forwardDetermine if the following salt is neutral, acidic or basic. If acidic or basic, write the appropriate equilibrium equation for the acid or base that exists when the salt is dissolved in aqueous solution. If neutral, simply write only NR. Be sure to include the proper phases for all species within the reaction. NaN₃arrow_forward
- A. Draw the structure of each of the following alcohols. Then draw and name the product you would expect to produce by the oxidation of each. a. 4-Methyl-2-heptanol b. 3,4-Dimethyl-1-pentanol c. 4-Ethyl-2-heptanol d. 5,7-Dichloro-3-heptanolarrow_forwardWhat is the pH of a 1.0 L buffer made with 0.300 mol of HF (Ka = 6.8 × 10⁻⁴) and 0.200 mol of NaF to which 0.160 mol of NaOH were added?arrow_forwardCan I please get help with this.arrow_forward
- Determine if the following salt is neutral, acidic or basic. If acidic or basic, write the appropriate equilibrium equation for the acid or base that exists when the salt is dissolved in aqueous solution. If neutral, simply write only NR. Be sure to include the proper phases for all species within the reaction. N₂H₅ClO₄arrow_forwardPlease help me with identifying these.arrow_forwardCan I please get help with this?arrow_forward
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning

