Question

What amino acid is formed using the N-phthalimidomalonic ester synthesis when the following alkyl halides are used in the third step?

(a)

(b) ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{SCH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{Br}$

Short answer

Answer:

(a)

(b)

Step-by-step solution

Ester synthesis

Amino acids can be synthesized with better yields than those obtained by the previous two methods (HVZ reaction and reductive amination) via an N-phthalimidomalonic ester synthesis, a method that combines the malonic ester synthesis and the Gabriel synthesis.

Formation of respective amino acids

Leucine is an essential amino acid that is used in the biosynthesis of proteins. It is an $\mathrm{\alpha }$amino acid as it contains an $\mathrm{\alpha }$amino group and a $\mathrm{\alpha }$carboxyl group. The mechanism of the reaction is represented as follows:

Formation of Leucine

Methionine is formed by the reaction of ester with the given alkyl halide. The mechanism of the reaction is represented as follows:

Formation of methionine