What alkyl bromide should be used in the acetoacetic ester synthesis of each of the following methyl
ketones?
c. 4-phenyl-2-butanone

Verified step by step guidance

1. Identify the target methyl ketone, which is 4-phenyl-2-butanone.
2. Recall that acetoacetic ester synthesis involves the alkylation of an acetoacetic ester followed by decarboxylation to form a methyl ketone.
3. Determine the structure of the acetoacetic ester anion, which is the enolate ion of ethyl acetoacetate.
4. Identify the alkyl group that needs to be added to the acetoacetic ester to form the desired ketone. In this case, the alkyl group is 3-phenylpropyl.
5. Select the appropriate alkyl bromide for the alkylation step. The alkyl bromide should be 3-phenylpropyl bromide.

Key Concepts

Acetoacetic Ester Synthesis

Acetoacetic ester synthesis is a method for forming ketones through the reaction of an acetoacetic ester with an alkyl halide. This process involves the nucleophilic substitution of the ester enolate with the alkyl halide, leading to the formation of a new carbon-carbon bond. Understanding this reaction is crucial for determining the appropriate alkyl bromide to use for synthesizing specific ketones.

Enolate Formation

Enolate formation is a key step in acetoacetic ester synthesis, where a base abstracts a proton from the alpha carbon of the acetoacetic ester, generating a resonance-stabilized enolate ion. This enolate can act as a nucleophile, attacking an electrophile such as an alkyl halide. Recognizing how to form and utilize enolates is essential for predicting the products of the synthesis.

Alkyl Halides

Alkyl halides, such as alkyl bromides, are organic compounds containing a carbon atom bonded to a halogen atom. In the context of acetoacetic ester synthesis, the choice of alkyl halide influences the structure of the resulting ketone. Understanding the reactivity and structure of different alkyl halides is vital for selecting the correct one to achieve the desired methyl ketone product.