Q23-3P - Organic Chemistry (Mcmurry)

Question

What enone product would you expect from aldol condensation of each of the following compounds?

Step-by-Step Solution

Answer

ENONE contains 𝛂 – 𝛃 unsaturated carbonyl compound having alkene which is conjugated to ketone in the same compound.

Step 1: (a) first product is:

Step 2: (b) second product is:

Step 3: (c) third product is:

$$\begin{gathered} {\mathrm{CH}}_3-\mathrm{CH}-{\mathrm{CH}}_2-\stackrel{\mathrm{O}}{\stackrel{\parallel }{\mathrm{C}}}-\mathrm{H}+{\mathrm{CH}}_2\mathrm{CHO} \\ | | \\ {\mathrm{CH}}_3 {\mathrm{H}}_3\mathrm{C}-\mathrm{CH} \\ | \\ {\mathrm{CH}}_3 \end{gathered}$$

${\mathrm{E}}_{\mathrm{t}}OH\uparrow \downarrow {\mathrm{N}}_{\mathrm{a}}\mathrm{OH}$

$$\begin{gathered} \stackrel{OH}{|} \stackrel{O}{\left|\right|} \\ C{H}_3—CH—C{H}_2—C—CH—CH \\ | | | \\ C{H}_3 H CH{\left(C{H}_3\right)}_2 \end{gathered}$$

                        

                $\uparrow \downarrow \overline{)heat}$ $$\begin{gathered} {\left(C{H}_3\right)}_2-CH-C{H}_2-CH=C-CHO \\ | \\ CH{\left(C{H}_3\right)}_2 \\ +H_{2}O \end{gathered}$$