Question

Question: Identify the reagents (a–h) needed to carry out each reaction.

Short answer

Answer

$$\begin{gathered} \mathrm{a}.{\mathrm{PBr}}_3 \\ \mathrm{b}.{\mathrm{tBuO}}^{-}{\mathrm{K}}^{+} \\ \mathrm{c}.\mathrm{TsCl},\mathrm{Pyridine} \\ \mathrm{d}.{\mathrm{tBuO}}^{-}{\mathrm{K}}^{+} \\ \mathrm{e}.{\mathrm{H}}_2{\mathrm{SO}}_4 \\ \mathrm{f}.{\mathrm{tBuO}}^{-}{\mathrm{K}}^{+} \\ \mathrm{g}.\mathrm{NaH} \\ \mathrm{h}.{\mathrm{OH}}^{-}/{\mathrm{H}}_2\mathrm{O} \end{gathered}$$

Step-by-step solution

Step-by-Step Solution Step 1: Conversion of alcoholic group to bromo

Alkyl halides can be converted to alkyl bromide using the reagent ${\mathbf{PBr}}_{\mathbf{3}}$. The bromocyclohexane hence formed, can be reduced using a strong base such as tert-butyloxide. The reaction is shown below:

Conversion of cyclohexanol to bromocyclohexane and reduction

The hydroxyl group of cyclohexanol can also be converted to a tosylate group and reduced in the same manner as shown below:

Tosylation and reduction

The hydroxyl group is reduced using a strong acid, converted to bromo cyclohexene using NBS, and reduced using a strong base.

Reduction of alcohol and further reactions

The halohydrination of cyclohexene is done using HOCl, which is further converted to an epoxide via reduction and then to a diol using a hydroxyl ion source.

Halohydrination, epoxidation, and formation of diol