`H_(3)C-Mg-Br+H_(2)C=CH-overset(O)overset(||)(C)-H overset(H_(3)O^(+))to ` product?

Options

A. `CH_(2)=CH-underset(CH_(2))underset(|)overset(OH)overset(|)(C)-H`
B. `H_(3)C-CH_(2)-CH_(2)-underset(O)underset(||)(C)-H`
C. `H_(2)underset(OH)underset(|)(C)-CH=CH-CH_(3)`
D. none

Answer

To solve the given question involving the reaction of a Grignard reagent with an alkene and a carbonyl compound, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants are:
- Grignard reagent: \( \text{H}_3\text{C-Mg-Br} \) (Methylmagnesium bromide)
- Alkene and carbonyl compound: \( \text{H}_2\text{C}=\text{CH-C(=O)-H} \) (This is an allylic alcohol, specifically 3-butenal)

2. **Understand the Role of the Grignard Reagent**:
The Grignard reagent acts as a nucleophile. It will attack the electrophilic carbon of the carbonyl group (the carbon of the C=O bond) in the 3-butenal.

3. **Nucleophilic Attack**:
The nucleophilic carbon of the Grignard reagent (\( \text{H}_3\text{C}^- \)) will attack the carbonyl carbon of the aldehyde group in 3-butenal:
\[ \text{H}_3\text{C-Mg-Br} + \text{H}_2\text{C}=\text{CH-C(=O)-H} \rightarrow \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 + \text{MgBr}^+ \]
This results in the formation of a tetrahedral intermediate.

4. **Formation of the Alkoxide Intermediate**:
After the nucleophilic attack, we will have an alkoxide intermediate:
\[ \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 \]
Here, the oxygen will carry a negative charge (\( \text{O}^- \)).

5. **Hydrolysis**:
The next step involves hydrolysis, where the alkoxide intermediate will react with water (from the \( \text{H}_3\text{O}^+ \) in the reaction):
\[ \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 + \text{H}_2\text{O} \rightarrow \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 + \text{MgBr}^+ + \text{OH}^- \]
This results in the final product being a secondary alcohol.

6. **Final Product**:
The final product of the reaction is:
\[ \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 \]
This is 3-methyl-2-buten-1-ol.

### Conclusion:
The product formed from the reaction of \( \text{H}_3\text{C-Mg-Br} \) with \( \text{H}_2\text{C}=\text{CH-C(=O)-H} \) followed by hydrolysis is:
\[ \text{H}_3\text{C-C(OH)(H)-CH=CH}_2 \]