Skip to main content
Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
Chapter 25, Problem 51a

Show how you would synthesize the following amino acids using the Strecker amino acid synthesis.
a. Ala

Verified step by step guidance
1
Identify the starting materials for the Strecker synthesis: an aldehyde, ammonia, and hydrogen cyanide. For alanine (Ala), the corresponding aldehyde is acetaldehyde (CH₃CHO).
React acetaldehyde with ammonia (NH₃) to form an imine intermediate. This step involves the nucleophilic attack of the ammonia on the carbonyl carbon of the aldehyde, followed by the elimination of water.
Add hydrogen cyanide (HCN) to the imine. The cyanide ion (CN⁻) will attack the imine carbon, leading to the formation of an aminonitrile intermediate.
Hydrolyze the aminonitrile under acidic conditions. This step involves converting the nitrile group (C≡N) into a carboxylic acid group (COOH), resulting in the formation of the amino acid.
Finally, isolate and purify the synthesized alanine. This may involve techniques such as crystallization or chromatography to obtain the pure amino acid product.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Strecker Amino Acid Synthesis

The Strecker synthesis is a method used to synthesize α-amino acids from aldehydes or ketones. It involves the reaction of an aldehyde with ammonium chloride and potassium cyanide to form an α-aminonitrile, which is then hydrolyzed to yield the amino acid. This method is significant for its simplicity and ability to produce a variety of amino acids.
Recommended video:
1:39
Synthesis of Amino Acids: Strecker Synthesis Concept 1

Amino Acid Structure

Amino acids are organic compounds composed of an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a distinctive side chain (R group) attached to a central carbon atom. The side chain determines the properties and identity of the amino acid. For alanine (Ala), the side chain is a simple methyl group (-CH3).
Recommended video:
Guided course
11:14
Charged Amino Acids

Hydrolysis of Nitriles

Hydrolysis of nitriles is a chemical reaction where a nitrile is converted into a carboxylic acid in the presence of water and an acid or base catalyst. In the context of Strecker synthesis, the α-aminonitrile intermediate undergoes hydrolysis to form the corresponding α-amino acid. This step is crucial for completing the synthesis of the desired amino acid from the nitrile intermediate.
Recommended video:
1:09
Review of Nitriles Concept 6