End product D of reaction sequence is `CH_3Broverset(KCN)rarrAoverset(H_2"O"//H^+)rarrBoverset(SOCl_2)rarrCoverset((C_2H_5)_2Cd)rarrD`

Options

A. `CH_3CH_2-O-C_2H_5`
B. `C_2H_5COOCH_3`
C. `CH_3COC_2H_5`
D. `CH_3COOC_2H_5`

Answer

To solve the question regarding the end product D of the reaction sequence starting from CH3Br, we will break down each step of the reaction sequence systematically.

### Step 1: Reaction of CH3Br with KCN
- **Reaction**: CH3Br + KCN → CH3CN (Acetonitrile)
- **Explanation**: Methyl bromide (CH3Br) reacts with potassium cyanide (KCN). The nucleophilic cyanide ion (CN-) attacks the electrophilic carbon in CH3Br, leading to the formation of acetonitrile (CH3CN) and the elimination of KBr.

### Step 2: Hydrolysis of Acetonitrile
- **Reaction**: CH3CN + H2O/H+ → CH3COOH (Acetic Acid)
- **Explanation**: Acetonitrile undergoes hydrolysis in the presence of water and an acid catalyst (H+) to form acetic acid (CH3COOH). The cyano group (-CN) is converted into a carboxylic acid (-COOH) during this process.

### Step 3: Reaction of Acetic Acid with Thionyl Chloride (SOCl2)
- **Reaction**: CH3COOH + SOCl2 → CH3COCl (Acetyl Chloride)
- **Explanation**: Acetic acid reacts with thionyl chloride to produce acetyl chloride (CH3COCl). This reaction involves the conversion of the -OH group in acetic acid to a -Cl group, resulting in the formation of an acid chloride.

### Step 4: Reaction of Acetyl Chloride with Diethyl Cadmium
- **Reaction**: CH3COCl + (C2H5)2Cd → CH3C(O)(C2H5)Cl
- **Explanation**: Diethyl cadmium ((C2H5)2Cd) acts as a nucleophile and attacks the carbonyl carbon in acetyl chloride. This results in the formation of a tetrahedral intermediate, which then collapses, leading to the elimination of chloride ion (Cl-) and the formation of the final product.

### Step 5: Final Product Formation
- **Final Product**: CH3C(O)C2H5
- **Explanation**: After the elimination of Cl-, the final product formed is methyl ethyl ketone (also known as 3-pentanone), which has the structure CH3C(O)C2H5.

### Conclusion
The end product D of the reaction sequence is methyl ethyl ketone, represented as CH3COC2H5.

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