Concept explainers
Interpretation:
A model of chair cyclohexane corresponding to the leftmost model in the given figure is to be drawn. The two reasons corresponding to the fact that the half-chair conformation is less stable than the chair or twist-boat conformation is to be stated.
Concept introduction:
The conformation of cyclohexane is a type of
Answer to Problem 7.1P
A model of chair cyclohexane corresponding to the leftmost model in the given figure is shown below.
The half-chair conformation is less stable than the chair or twist-boat conformation because half-chair conformation has maximum ring strain and the presence of angle strain in half-chair conformation of cyclohexane molecule.
Explanation of Solution
The given leftmost figure of chair conformation of cyclohexane is shown as,
Figure 1
The model of chair conformation of cyclohexane corresponding to the leftmost model is shown as,
Figure 2
If the carbon-4 in order to locate carbons 2-5 in a common plane then the above model chair conformation of cyclohexane is shown as,
Figure 3
Thus, the raising of carbon-4 in order to locate carbons 2-5 in a common plane forms the half-chair conformation of cyclohexane molecule. This half-chair conformation of cyclohexane molecule is a transition state for the conversion into the chair and twist boat conformations.
The two reasons which explain that the half-chair conformation is less stable than the chair or twist-boat conformation are as follows.
• The ring strain in half chair conformation is more as compared to the chair or twist-boat conformation.
• The angle strain of
A model of chair cyclohexane corresponding to the leftmost model in the given figure has been shown above. The two reasons corresponding to the fact that the half-chair conformation is less stable than the chair or twist-boat conformations has been stated above.
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Chapter 7 Solutions
Organic Chemistry
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Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning