Question

Predict the products of these reaction sequences.

Short answer

LDA is the lithium di-isopropylamide $\left(C_4{H}_{9}Li\right)$ it is the strong base used to protonate the acidic hydrogen to form lithium enolate.

Step-by-step solution

Step-by-Step SolutionStep 1: Reaction with LDA

LDA is the lithium di-isopropylamide $\left(C_4{H}_{9}Li\right)$ it is the strong base used to protonate the acidic hydrogen to form lithium enolate.

Cross Aldol condensation

It is the reaction of the enolate ion with carbonyl group other than reacting carbonyl species which leads to forming$\mathbf{\alpha }\mathbf{,}\mathbf{\beta }$ unsaturated aldehyde or ketone.

It is also called mixed aldol condensation because reacting carbonyl is react with different carbonyls to form the product.

Formation of the product

As the hydrogen is protonated from the reacting species formation of enolate ion occurs which combines carbonyl other than reacting carbonyl species followed by the removal of formation of unsaturated aldehyde occur.

Reaction with LDA followed by cross aldol condensation

1. Deprotonation of hydrogen
2. Enolate formed
3. Cross aldol condensation

Product Formation