1-Ethyl-2-methyl oxirane when treated with `C_2 H_5 MgBr`, followed by hydrolysis gives :

Options

A.
B.
C.
D.

Explanation

To solve the question, we need to follow the reaction steps involving 1-Ethyl-2-methyl oxirane and the Grignard reagent, ethyl magnesium bromide (C2H5MgBr), followed by hydrolysis. Here’s the step-by-step solution:

### Step 1: Identify the Reactants
1-Ethyl-2-methyl oxirane is an epoxide (cyclic ether) with the following structure:
- The oxirane ring consists of three members: one oxygen atom and two carbon atoms.
- The carbon atoms are substituted with an ethyl group (C2H5) and a methyl group (CH3).

### Step 2: React with Grignard Reagent
When 1-Ethyl-2-methyl oxirane is treated with ethyl magnesium bromide (C2H5MgBr), the Grignard reagent acts as a nucleophile. The nucleophilic carbon in the Grignard reagent will attack the less hindered carbon atom of the oxirane ring, leading to the opening of the epoxide ring.

### Step 3: Formation of the Alkoxide Intermediate
The reaction will result in the formation of an alkoxide intermediate. The structure of the alkoxide will be:
- The ethyl group from the Grignard reagent will attach to the carbon atom that was originally bonded to the ethyl group in the oxirane.
- The remaining carbon will be attached to the methyl group.

The resulting structure will be:
- A carbon atom with an ethyl group (from Grignard) and a methyl group, and an alkoxide (O-MgBr) attached.

### Step 4: Hydrolysis
The next step is hydrolysis, where the alkoxide is treated with water (or an acid). During hydrolysis:
- The alkoxide will convert to an alcohol.
- The magnesium bromide (MgBr) will react with water to form magnesium hydroxide (Mg(OH)Br).

### Step 5: Final Product
After hydrolysis, the final product will be:
- The alcohol derived from the alkoxide, which will have the structure of 1-Ethyl-2-methyl ethanol (C2H5-CH(OH)-CH3).

### Conclusion
The final product after treating 1-Ethyl-2-methyl oxirane with C2H5MgBr followed by hydrolysis is **1-Ethyl-2-methyl ethanol**.

### Answer
The answer is **1-Ethyl-2-methyl ethanol**.

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