Question

Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.

• A. $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COCl}$ and $\mathrm{NH}_{2}-\mathrm{CH}-\mathrm{COOH}$
• B. $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COCl}$ and $\mathrm{NH}_{3}-\mathrm{CH}-\mathrm{COCl}$
• C. $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COOH}$ and $\mathrm{NH}_{2}-\mathrm{CH}-\mathrm{COCl}$
• D. $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COOH}$ and $\mathrm{NH}_{2}-\mathrm{CH}-\mathrm{COOH}$

Hint:

The formation of a dipeptide involves the reaction between an amino acid and its chloride derivative with the elimination of HCl.

Answer 1

The Correct Option is A

1. Reactants: - $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COCl}$ (Glycine chloride) - $\mathrm{NH}_{2}-\mathrm{CH}-\mathrm{COOH}$ (Alanine) 
2. Reaction: - The reaction between these reactants with the elimination of HCl will produce the dipeptide Gly-Ala. 
Therefore, the correct answer is (1) $\mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COCl}$ and $\mathrm{NH}_{2}-\mathrm{CH}-\mathrm{COOH}$.