The major product [B] in the following sequence of reaction is having how many `sp^3` hybridized Carbon atoms ?
` ``(CH_(3)-underset(CH(CH_3)_2)underset(|)C=CH-CH_2CH_3)underset((ii)H_2O_2,OH^(Theta))overset((i)B_2H_6)rarr[A]underset(Delta)overset("dil."H_2SO_4)rarr[B]`

Answer

To determine the number of sp³ hybridized carbon atoms in the major product [B] from the given reaction sequence, we will follow these steps:

### Step 1: Identify the starting compound
The starting compound is:
\[ \text{(CH}_3\text{-C(CH}_3)_2\text{-C}=\text{CH-CH}_2\text{CH}_3) \]
This compound has a double bond between the carbon atoms.

### Step 2: Hydroboration reaction
The first reaction involves hydroboration using \( B_2H_6 \) followed by oxidation with \( H_2O_2 \) and \( OH^- \). In this step, the reaction follows the anti-Markovnikov rule, meaning that the hydrogen will add to the less substituted carbon of the double bond.

The product \( A \) after hydroboration and oxidation will be:
\[ \text{(CH}_3\text{-C(CH}_3)_2\text{-C(OH)-CH}_2\text{CH}_3) \]

### Step 3: Acid-catalyzed dehydration
Next, the product \( A \) is treated with dilute \( H_2SO_4 \) and heated, leading to dehydration. The hydroxyl group (-OH) will be protonated to form a good leaving group, resulting in the formation of a carbocation.

### Step 4: Carbocation rearrangement
The carbocation formed will undergo rearrangement (hydride shift) to form a more stable tertiary carbocation. The product \( B \) will be formed after elimination of water.

### Step 5: Determine the structure of product \( B \)
The major product \( B \) can be represented as:
\[ \text{(CH}_3\text{-C(CH}_3)_2\text{-C}=\text{C-CH}_2\text{CH}_3) \]
This structure contains double bonds and single bonds.

### Step 6: Count sp³ hybridized carbon atoms
To identify the sp³ hybridized carbon atoms, we look for carbon atoms that are bonded to four other atoms (which can be hydrogen or other carbons).

- The carbon atoms in the structure can be analyzed:
1. The terminal \( CH_3 \) group (1 sp³)
2. The \( CH \) groups attached to the \( C(CH_3)_2 \) (2 sp³)
3. The \( CH_2 \) groups (2 sp³)

In total, we find that there are **6 sp³ hybridized carbon atoms** in product \( B \).

### Final Answer
The major product [B] has **6 sp³ hybridized carbon atoms**.

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