Organic Chemistry

(Jacob Rumans) #1
Other cycloalkanes

Note: In the above models, the straight lines represesnt single bonds, the lumps represent
carbon atoms, and the open ends represent hydrogen atoms.


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The chair conformation (can you see how it looks like a chair?) is lower in energy than
the boat conformation. This is because the two ends of the molecule are farther apart and
avoid steric hinderance.


Hydrogen atoms in a cyclohexane can be divided into two types:


1.Axial, that point towards the top and bottom, and
2.Equitorial, that point out away from the edge of the molecule

When hydrogens are replaced with other, bulkier groups, it becomes apparent that the axial
positions are less energetically favored than the equitorial positions. That means that, if
given a choice, bulkier groups will tend to bond to cyclohexane in equitoral positions, as
this reduces their steric hinderance and potential energy.


26.6 Other cycloalkanes


Cyclopentaneflips between slightly different conformers as well.


4 https://en.wikibooks.org/wiki/..%2F..%2FPlaces%20to%20buy%20organic%20chemistry%20models

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