Q43E - Organic Chemistry (Mcmurry)

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

Step-by-Step Solution

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 1: (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)

Step 2: (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)

Step 3: (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)

Step 4: (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.