Question: What alkyl halides would you use to prepare the following ketones by an acetoacetic ester synthesis?

The alkyl halides which you need to use to prepare ketone (a) is 1-bromo-2-methylpropane.

The product of this reaction is

Hence, the$-C{H}_{2}COC{H}_3$comes from acetoacetic ester.

The remaining part ${\left(C{H}_3\right)}_{2}CHC{H}_2$ comes from alkyl halide (1-bromo-2-methylpropane).

Now the mechanism of this reaction is

The alkyl halide which you need to use to prepare the given ketone (a) by acetoacetic ester is 1-bromo-2-methylpropane.

The alkyl halides which you need to use to prepare ketone (b) is 1-bromo-2-phenylethane.

The product of this reaction is

Hence, the –CH₂COCH₃ comes from acetoacetic ester.

The remaining part C₆H₅CH₂CH₂- comes from alkyl halide (1-bromo-2-phenylethane).

Now the mechanism of this reaction is

The alkyl halide which you need to use to prepare the given ketone (b) by acetoacetic ester is 1-bromo-2-phenylethane.