(Solved): 5. A substitution reaction is performed on the compound below to replace the bromine atom with a ni ...

5. A substitution reaction is performed on the compound below to replace the bromine atom with a nitrile (-C $?\mathrm{N})$ group. The reaction follows an ${\mathrm{S}}_{\mathrm{N}}2$ mechanism. Draw the nucleophile and product(s) of this reaction, showing any stereochemistry. "Mastery" (i.e. merit-grade) questions 6. Draw a curly arrow mechanism for the reaction shown in question 5 . 7. Below is shown the outcome of treating (R)-3-bromo-3-methylnonane with methanol. Notice that the starting material reacts to give a racemic mixture of products. Draw a mechanism to explain why. $\stackrel{{\mathrm{CH}}_3\mathrm{OH}}{?}$ (R)-3-bromo-3-methylnonane $(R)$ - and (S)-3-methoxy-3-methylnonane 8. Below is a blank energy vs reaction coordinate diagram for the following nucleophilic substitution reaction: $\stackrel{\mathrm{NaCN}}{?}$ (a) Indicate whether the reaction follows an ${\mathrm{S}}_{\mathrm{N}}1$ or ${\mathrm{S}}_{\mathrm{N}}2$ mechanism. (b) Label the diagram with: i. The reactants and the products ii. The activation energy $\left(E_{\mathrm{a}}\right)$ for the rate limiting step iii. The free energy change for the reaction $(?G)$ iv. The transition state or intermediate, as appropriate