Question

Which, if any, of the following compounds can be prepared by a malonic ester synthesis? Show the alkyl halide you would use in each case.

(a)Ethyl pentanoate (b)Ethyl 3-methylbutanoate

(c)Ethyl 2-methylbutanoate (d) Ethyl 2,2-dimethylpropanoate

Short answer

(a) Ethyl pentanoate can be synthesized from malonic ester synthesis.

(b) Ethyl 3-methylbutanoate can be synthesized from malonic ester synthesis.

(c) Ethyl 2-methylbutanoate can be synthesized from malonic ester synthesis

(d) Ethyl 2,2-dimethylpropanoate cannot be synthesized from malonic ester synthesis

Step-by-step solution

(a) Preparation of Ethyl pentanoate

The given compound, Ethyl pentanoate can be prepared from malonic ester synthesis.

The reaction is given below,

Chemical reaction (a)

(b) Preparation of Ethyl 3-methylbutanoate

The given compound, Ethyl 3-methylbutanoate can be prepared from malonic ester synthesis.

The reaction is given below,

Chemical reaction (b)

(c) Preparation of Ethyl 2-methylbutanoate

The given compound, Ethyl 2-methylbutanoate can be prepared from malonic ester synthesis.

The reaction is given below,

Chemical reaction (c)

(d) Preparation of Ethyl 2,2-dimethylpropanoate

The given compound, Ethyl 2,2-dimethylpropanoate cannot be prepared from malonic ester synthesis.

From malonic ester, we can only prepare mono or di-substituted acetyl ester.