Question

Show how you would synthesizefrom each compound. You may use any necessary reagents.

(a) heptanal

(b)$\text{oct - 1 - yne}$

(c) $\text{2,3 - dimethylnon - 2 - ene}$

(d)$\text{octan - 2 - ol}$

(e) heptanoic acid

(f) ${\text{CH}}_{\text{3}}{\text{(CH}}_{\text{2}}{\text{)}}_{\text{5}}\text{CN}$

Short answer

The structure for $\text{octan - 2 - one}$is shown below

$\text{octan - 2 - one}$

Step-by-step solution

Octan-2-one

The structure for $\text{octan - 2 - one}$is shown below

$\text{octan - 2 - one}$

Synthetic methodology

(a) Heptanal on treatment with a Grignard reagent ( methylmagnesium bromide) and ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ gives $\text{octan - 2 - ol}$ which on further reaction with PCC (pyridinium chlorochromate) oxidizes the secondary alcohol to ketone. The final product formed is$\text{octan - 2 - one}$

$\text{reaction} \text{a}$

(b) Oxyemercuration of$\text{oct - 1 - yne}$ (alkene) takes place with${\text{HgSO}}_4$ and${\text{H}}_{\text{2}}\text{O}$ to give the product as $\text{octan - 2 - one}$ (ketone).

$\text{reaction} \text{b}$

(c) Ozone cleaves the double bonds similar to permanganate to give ketones and aldehydes. $\text{2,3 - dimethylnon - 2 - ene}$undergoes ozonolysis to give the products as $\text{octan - 2 - one}$and $\text{propan - 2 - one}$.

$\text{reaction} \text{c}$

(d) $\text{octan - 2 - ol}$which reaction with PCC (pyridinium chlorochromate) oxidizes the secondary alcohol to ketone. The final product formed is $\text{octan - 2 - one}$

$\text{reaction} \text{d}$

(e) Heptanoic acid on treatment with an organlithium reagent ( methyllithium) and then ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$gives $\text{octan - 2 - one}$.

$\text{reaction} \text{e}$

(f) Heptanenitrile on treatment with a Grignard reagent ( methylmagnesium bromide) and ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$gives $\text{octan - 2 - one}$ .

$\text{reaction} \text{f}$