Describe how the following synthesis can be carried out:
Use any required reagents and solvents.

Flowchart of synthesis steps using HBr and lithium reagents for carboxylation.

Flowchart of synthesis steps using HBr and magnesium reagents for carboxylation.

Flowchart of synthesis steps using HBr and lithium reagents for carboxylation with CO2.

Flowchart of synthesis steps using HBr and magnesium reagents for carboxylation with CO2.

Describe how the following synthesis can be carried out:Use any required reagents and solvents.