Question

Show how you would accomplish the following multistep conversions. You may use any additional reagents you need.

Short answer

a.

b.

c.

d.

Step-by-step solution

Step-by-Step SolutionStep 1: Claisen ester condensation

In this sodium ethoxide is used for condensation to avoid transesterification. Ethoxide is the base which protonates the acidic hydrogen to form $\mathbf{\beta }$keto ester.

Formation of the product followed by alkylation

Ethoxide is used as a base to form enolate ions which form $\mathrm{\beta }$keto ester on further reaction with the alkyl halide the alkylation occurs means the removal of halide ion in the alkyl group attached at the alpha position to the carbonyl.

Mechanism of compound A

1. Acidic hydrogen protonated
2. Formation of the enolate ion
3. Dieckmann’s reaction
4. Alkylation
5. Hydrolysis

Reaction Mechanism

Mechanism of compound B

1. Acidic hydrogen protonated
2. Formation of enolate ion
3. Alkylation
4. Formation of alkene by adding base to remove halogen
5. Hydrolysis

Mechanism of compound C

1. Acidic hydrogen protonated
2. Formation of the enolate ion
3. Robinson reaction followed by an aldol reaction
4. Formation of alkane by reducing alkene in presence of Lindlar’s catalyst

Substitution of phenyl ring

Mechanism of compound D

1. Acidic hydrogen protonated
2. Formation of enolate ion
3. Claisen condensation
4. Alkylation