Predict the predict of the reaction with $\mathrm{HBr}$ with (i) cyclopropane (ii) $1,1-$dimethylcyclpropane

Compare the rates of these reactions.

(b) Calculate the $∆{\mathrm{H}}_{\mathrm{c}}$ per ${\mathrm{CH}}_2$ unit for the first six cycloalkanes. The $∆{\mathrm{H}}_{\mathrm{c}}$ 's in $\mathrm{kJ}/\mathrm{mol}$ are: cyclopropane $-2090$; cyclobutane $-2718$; cyclopentane $-3288$, cyclohexane $-3918$, cycloheptane -4632, cycloocatne $-5304$.

How do the calculated values in (b) relate to the ring stability?

What factor causes rings to have different stabilities?

Generalize about ring size, ring strain and stability for the first four $\text{cycloalkanes}$.

Compare the orbital overlap in cyclopropane with that in alkanes.

Complete the following reactions:

${\mathrm{H}}_2\mathrm{C}={\mathrm{CH}}_2+{\mathrm{CH}}_2{\mathrm{N}}_2 \left(\mathrm{diazomethane}\right)\stackrel{}{\to }?$

Complete the following reaction.

${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CH}}_2+{\mathrm{CH}}_2{\mathrm{I}}_2\stackrel{\mathrm{Cu}-\mathrm{Zn}}{\to }$