Q23-6P - Organic Chemistry (Mcmurry)

Question

1-Butanol is prepared commercially by a route that begins with an aldol reaction. Show the steps that are likely to be involved.

Step-by-Step Solution

Answer

The reaction includes aldol condensation followed by reduction using suitable reagents.

Step 1:

Aldol condensation of ethanol in the presence of a base like NaOH and then heating the compound gives:

$$\begin{gathered} \mathrm{O} \mathrm{O} \\ \left|\right| \left|\right| \\ {\mathrm{CH}}_3-\mathrm{CH}\underset{2.\mathrm{Heat}}{\overset{1.{\mathrm{N}}_{\mathrm{a}}\mathrm{OH},{\mathrm{E}}_{\mathrm{t}}\mathrm{OH}}{\to }}{\mathrm{CH}}_3\mathrm{CH}=\mathrm{C}-\mathrm{C}-\mathrm{H} \\ | \\ \mathrm{H} \end{gathered}$$

Step 2:

Now reduction is done by selective reducing agent NaBH₄and followed by hydrogenation reaction in presence of Pd/Pt give 1-butanol:

$$\begin{gathered} {\mathrm{CH}}_3\mathrm{CH}=\mathrm{C}-\mathrm{C}-\mathrm{H} \underset{2.\mathrm{Heat}}{\overset{1.{\mathrm{N}}_{\mathrm{a}}\mathrm{OH},{\mathrm{E}}_{\mathrm{t}}\mathrm{OH}}{\to }} {\mathrm{CH}}_3-\mathrm{CH}={\mathrm{CHCH}}_2\mathrm{OH} \\ | {\mathrm{H}}_{2,}\mathrm{Pd}/\mathrm{c}\downarrow \\ \mathrm{H} \\ {\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{OH} \end{gathered}$$

                                                                            1-Butanol