`R-overset(O)overset(||)C-H+ NH_3 + HCN to A overset(H_3 O^(+))to B` respectively A and B can be

Answer

To solve the problem, we will break down the reaction step by step, identifying the compounds A and B formed during the process.

### Step 1: Identify the Reactants
The reaction starts with an aldehyde (R-CHO), ammonia (NH₃), and hydrogen cyanide (HCN).

### Step 2: Protonation of the Aldehyde
The aldehyde (R-CHO) is protonated by an acid (H₃O⁺) to form a more electrophilic species. This step enhances the reactivity of the carbonyl carbon.

**Hint:** Protonation increases the electrophilicity of the carbonyl carbon.

### Step 3: Nucleophilic Attack by Ammonia
Ammonia (NH₃) acts as a nucleophile and attacks the electrophilic carbon of the protonated aldehyde. This results in the formation of an intermediate that has both an amine (NH₂) and a hydroxyl (OH) group.

**Hint:** Remember that nucleophiles attack electrophilic centers.

### Step 4: Formation of the Iminium Ion
The intermediate undergoes dehydration (loss of water) to form an iminium ion (R-NH=CH₂). This step is crucial as it sets the stage for the next nucleophilic attack.

**Hint:** Dehydration often leads to the formation of double bonds in organic reactions.

### Step 5: Nucleophilic Attack by Cyanide Ion
The iminium ion is then attacked by the cyanide ion (CN⁻), leading to the formation of a new compound (R-NH-C≡N).

**Hint:** The cyanide ion is a strong nucleophile and can attack the iminium ion.

### Step 6: Hydrolysis of the Cyanohydrin
The product from the previous step undergoes hydrolysis in the presence of water (H₂O) and acid (H₃O⁺) to form a cyanohydrin (R-NH-CH(OH)-C≡N).

**Hint:** Hydrolysis typically involves the addition of water to break bonds.

### Step 7: Protonation and Formation of the Amino Acid
The cyanohydrin undergoes further reactions, including protonation and eventual hydrolysis, leading to the formation of an amino acid (R-NH₂-CH₂-COOH).

**Hint:** The final product is an amino acid, which contains both an amine and a carboxylic acid functional group.

### Summary of Products
- **Compound A:** The product after the nucleophilic attack of cyanide on the iminium ion, which can be represented as R-NH-C≡N.
- **Compound B:** The final amino acid product formed after hydrolysis, represented as R-NH₂-CH₂-COOH.

### Final Answer
- **A:** R-NH-C≡N (an intermediate compound)
- **B:** R-NH₂-CH₂-COOH (an amino acid)