Question

The following compounds can be synthesized by aldol condensations, followed by further reactions. (In each case, work backward from the target molecule to an aldol product, and show what compounds are needed for the condensation.)

Short answer

The reaction of the enolate ion with another carbonyl group leads to the form of$\mathrm{\alpha },\mathrm{\beta }$ unsaturated aldehyde or ketone.

Step-by-step solution

Step-by-Step Solution Step 1: Aldol self-condensation

The reaction of the enolate ion with another carbonyl group leads to the form of$\mathrm{\alpha },\mathrm{\beta }$ unsaturated aldehyde or ketone.

Formation of the product

As the hydrogen is protonated from the reacting species, the formation of enolate ion occurs, which combines with another group of carbonyl, followed by the removal of ${\mathrm{OH}}^{-}$formation of $\mathrm{\alpha },\mathrm{\beta }$unsaturated aldehyde occur.

To find reactant from the product

1. First, check the possible $\mathrm{\alpha },\mathrm{\beta }$unsaturated bond
2. By breaking the bond formation of aldehyde or ketone occur as per the reverse of aldol condensation
3. Because in the aldol condensation$\mathrm{\alpha },\mathrm{\beta }$ unsaturated bond is formed by the nucleophilic attack of two aldehyde or ketonic group.

Reverse and forward synthesis by aldol condensation

The reaction followed as given to find the reactant from the product and cross-check by forward synthesis.

Aldol Condensation