`CH-=CH underset(H_2SO_4)overset(HgSO_4)to underset(H_2O)overset(CH_3MgBr)to overset(P//Br_2)to`

Options

A. `CH_3CH(Br)CH_3`
B. `CH_3CH_2CH_2Br`
C. `CH_2=CH-Br`
D. `BrCH=CH-CH_3`

Explanation

To solve the given reaction sequence step by step, let's break down each part of the process:

### Step 1: Hydration of Alkyne
The reaction starts with an alkyne (specifically, CH≡CH). When treated with H₂SO₄ and HgSO₄, the alkyne undergoes hydration. This process adds water across the triple bond, resulting in the formation of a carbonyl compound (aldehyde or ketone).

**Reaction:**
\[ \text{CH≡CH} \xrightarrow{\text{H}_2\text{SO}_4, \text{HgSO}_4} \text{CH}_3\text{CHO} \]

**Product:** Acetaldehyde (CH₃CHO)

### Step 2: Reaction with Grignard Reagent
Next, the product (acetaldehyde) is treated with a Grignard reagent (CH₃MgBr). The Grignard reagent acts as a nucleophile and attacks the carbonyl carbon of the aldehyde.

**Reaction:**
\[ \text{CH}_3\text{CHO} + \text{CH}_3\text{MgBr} \rightarrow \text{CH}_3\text{C(OMgBr)H}_2 \]

This intermediate will then be hydrolyzed in the presence of water.

### Step 3: Hydrolysis
When the Grignard reagent intermediate is treated with water, it will form an alcohol.

**Reaction:**
\[ \text{CH}_3\text{C(OMgBr)H}_2 + \text{H}_2\text{O} \rightarrow \text{CH}_3\text{CH(OH)CH}_3 + \text{Mg(OH)Br} \]

**Product:** 2-Propanol (CH₃CH(OH)CH₃)

### Step 4: Reaction with PBr₂
Finally, the alcohol (2-propanol) reacts with phosphorus tribromide (PBr₂). This step replaces the hydroxyl group (OH) with a bromine atom (Br).

**Reaction:**
\[ \text{CH}_3\text{CH(OH)CH}_3 + \text{PBr}_2 \rightarrow \text{CH}_3\text{CHBrCH}_3 + \text{HBr} + \text{PO} \]

**Final Product:** 2-Bromopropane (CH₃CHBrCH₃)

### Summary of the Reaction Sequence:
1. CH≡CH + H₂SO₄ + HgSO₄ → CH₃CHO (Acetaldehyde)
2. CH₃CHO + CH₃MgBr → CH₃C(OMgBr)H₂
3. CH₃C(OMgBr)H₂ + H₂O → CH₃CH(OH)CH₃ (2-Propanol)
4. CH₃CH(OH)CH₃ + PBr₂ → CH₃CHBrCH₃ (2-Bromopropane)

Thus, the final product of the entire reaction sequence is **2-Bromopropane (CH₃CHBrCH₃)**.