What amino acid is formed using the N-phthalimidomalonic ester synthesis when the following alkyl halides are used in the third step? b. CH3SCH2CH2Br

Verified step by step guidance

1. Identify the starting material for the N-phthalimidomalonic ester synthesis, which is the N-phthalimidomalonic ester itself.
2. In the third step of the synthesis, the alkyl halide (in this case, CH3SCH2CH2Br) is used to alkylate the malonic ester derivative. This involves a nucleophilic substitution reaction where the carbanion generated from the malonic ester attacks the alkyl halide.
3. The carbanion is formed by deprotonating the methylene group between the two ester groups using a strong base, typically sodium ethoxide or sodium hydride.
4. The nucleophilic carbanion attacks the electrophilic carbon in the alkyl halide, displacing the bromide ion and forming a new carbon-carbon bond. This results in the formation of a substituted malonic ester with the side chain CH3SCH2CH2- attached.
5. After alkylation, the compound undergoes hydrolysis and decarboxylation to yield the corresponding amino acid. The side chain introduced in the alkylation step becomes the side chain of the amino acid.

Key Concepts

N-phthalimidomalonic ester synthesis

N-phthalimidomalonic ester synthesis is a method for synthesizing amino acids, particularly through the use of phthalimide and malonic ester. This reaction involves the formation of a phthalimide intermediate, which is then alkylated to introduce a side chain, followed by hydrolysis and decarboxylation to yield the final amino acid product.

Alkyl halides

Alkyl halides are organic compounds containing a carbon chain bonded to a halogen atom (such as bromine, chlorine, or iodine). In the context of the N-phthalimidomalonic ester synthesis, the choice of alkyl halide influences the structure of the resulting amino acid, as it determines the side chain that will be attached to the amino acid backbone during the alkylation step.

Amino acid structure

Amino acids are organic molecules that serve as the building blocks of proteins. Each amino acid has a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain (R group). The specific side chain determines the properties and identity of the amino acid, which is crucial for understanding how different alkyl halides will affect the final product in the synthesis process.