Question

Which of the following has maximum angle strain?
a) Cyclopropane
​b) Cyclobutane
​c) Cyclopentane
​d) Cyclohexane

Answer 1

More the number of carbon atom more will be the stability and has less angle strain. Thus cyclopropane has less stability and has more bond angle strain
$$\begin{gathered} Bondanglestrainofcyclopropane=\frac{1}{2}[{109}^0{28}^{\text{'}}-bondangleofthecyclopropane] \\ =\frac{1}{2}[{109}^0{28}^{\text{'}}-60]=\frac{{49}^0{28}^{\text{'}}}{2}={24}^0{58}^{\text{'}} \\ Bondanglestrainofcyclobu\tan e=\frac{1}{2}[{109}^0{28}^{\text{'}}-bondangleofthecyclobu\tan e] \\ =\frac{1}{2}[{109}^0{28}^{\text{'}}-90]=\frac{{19}^0{28}^{\text{'}}}{2}=9^0{58}^{\text{'}} \\ Bondanglestrainofcyclopen\tan e=\frac{1}{2}[{109}^0{28}^{\text{'}}-bondangleofthecyclopen\tan e] \\ =\frac{1}{2}[{109}^0{28}^{\text{'}}-108]=\frac{1^0{28}^{\text{'}}}{2}=0.{58}^{\text{'}} \\ Bondanglestrainofcyclohexane=\frac{1}{2}[{109}^0{28}^{\text{'}}-bondangleofthecyclohexane] \\ =\frac{1}{2}[{109}^0{28}^{\text{'}}-120]=\frac{-{10}^0{32}^{\text{'}}}{2}=-5^0{16}^{\text{'}} \end{gathered}$$