`(A)underset(250^@C)overset(Al_2O_3)to(B)underset((ii)AgOH)overset(HI)to( C)underset(150^@C)overset(Al_2O_3)to(B)underset((ii)H_2O_2, OH^(-))overset((i)B_2H_6)to(A)`
In the above reaction sequence (A) and ( C) are isomers.Molecular formula of B is `C_5H_10`.which can also be obtained form the product of the reaction with `CH_3CH_2MgBr` and `(CH_3)_2CO` are followed by acidification.
Identify the structure of A

Options

A. `CH_3-CH_2-CH_2-undersetunderset(OH)(|)CH-CH_3`
B. `(CH_3)_2CHCHOHCH_3`
C. `(CH_3)_3C-CH_3-OH`
D. `CH_3-CH_2-undersetunderset(OH)(|)CH-CH_2-CH_3`

Explanation

To identify the structure of compound A based on the provided reaction sequence, we can break down the steps as follows:

### Step 1: Analyzing the Reaction Sequence
1. **Starting with Compound A**: It reacts with Al₂O₃ at 250°C to form compound B.
2. **Compound B**: It has the molecular formula C₅H₁₀ and can be derived from the reaction of CH₃CH₂MgBr with (CH₃)₂CO (acetone) followed by acidification.
3. **Compound B Reacts with HI**: This leads to the formation of compound C.
4. **Compound C**: Reacts with AgOH and then with Al₂O₃ at 150°C to regenerate compound B.
5. **Final Step**: Compound C undergoes hydroboration-oxidation with B₂H₆ to regenerate compound A.

### Step 2: Identifying Compound B
Given that B has the molecular formula C₅H₁₀, we can deduce its structure:
- The reaction with Grignard reagent (CH₃CH₂MgBr) and acetone produces a tertiary alcohol.
- After dehydration, this tertiary alcohol would yield an alkene.

### Step 3: Determining the Structure of B
From the reaction with acetone and subsequent dehydration, the structure of compound B can be deduced:
- The tertiary alcohol formed from the Grignard reaction would be 2-pentanol (CH₃CH(OH)CH₂CH₃).
- Upon dehydration, it forms 2-pentene (C₅H₁₀).

### Step 4: Identifying Compounds A and C
Since A and C are isomers:
- Compound A is likely a secondary alcohol that can be dehydrated to form the same alkene as compound B.
- Compound C, being a product of the reaction with HI, is likely a tertiary alcohol.

### Step 5: Final Structures
- **Structure of B**: 2-pentene (CH₃CH=CHCH₂CH₃)
- **Structure of A**: 3-pentanol (CH₃CH(OH)CH₂CH₃)
- **Structure of C**: 2-pentanol (CH₃C(OH)(CH₃)CH₂CH₃)

### Conclusion
The structure of compound A is 3-pentanol (CH₃CH(OH)CH₂CH₃).