What alkyl halides are needed to prepare the given ketone using the acetoacetic ester synthesis?
Conversion Of Ethyl Acetoacetate Into a Ketone:
The conversion of ethyl acetoacetate into a ketone can be accomplished by a method known as acetoacetic ester synthesis. Ethyl acetoacetate reacts with a base and an alkyl halide to form a ketone in this method. The procedure is indeed very much comparable to that of malonic ester synthesis.
Answer and Explanation: 1
A retrosynthetic analysis, as shown below, is used to find the starting materials.
As shown below, a forward reaction pathway is used to achieve the product.
Ethyl-3-oxobutanoate or ethyl acetoacetate reacts with sodium ethoxide and 1-bromo-4-methylpentane to form ethyl-2-acetyl-6-methyl heptanoate, which upon heating produces 7-methyloctan-2-one.
The mechanism of the acetoacetic ester synthesis is represented below:
Ethoxide ion abstracts the acidic proton from the reactant, which acts as a nucleophile and attacks primary carbocation followed by removal of bromide ion known as an SN2 reaction. Then upon hydrolysis, the ester group is converted to acid. Then decarboxylation of carboxylic acid takes place to obtain the desired product.
Hence, the alkyl halide used to synthesize the given ketone is 1-bromo-4-methylpentane.
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fromChapter 3 / Lesson 16
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