`(A)(C_(4)H_(8)O)overset(H_(3)O^(o+))rarr(B)overset(CrO_(3))underset("acetic acid")rarr(C )overset(CH_(2)N_(2))underset(Delta)rarr(D)`
The compound 'D' is

Options

A.
B.
C.
D.

Answer

To solve the problem step by step, we need to analyze the transformations of the compound A (C₄H₈O) to find out what compound D is.

### Step 1: Identify Compound A
The molecular formula C₄H₈O suggests that compound A could be a simple alcohol or an ether. A common structure that fits this formula is CH₂=CH-CH₂-CH₂OH (butanol) or CH₃-CH₂-CH₂-CHO (butanal). However, for this problem, we will consider it as a primary alcohol, specifically 1-butanol (C₄H₈O).

### Step 2: Reaction of A with Acid
When 1-butanol (A) is treated with an acid (H₃O⁺), it can undergo a rearrangement or ring expansion. In this case, it can form cyclobutanol (B) through a ring formation reaction.

**B = Cyclobutanol**

### Step 3: Oxidation of B with CrO₃ and Acetic Acid
Cyclobutanol (B) is then oxidized using chromium trioxide (CrO₃) in acetic acid. This oxidation process typically converts alcohols to ketones or aldehydes. In this case, cyclobutanol is oxidized to cyclobutanone (C).

**C = Cyclobutanone**

### Step 4: Reaction of C with Diazomethane
Cyclobutanone (C) is then treated with diazomethane (CH₂N₂) under heating conditions. Diazomethane is known to react with carbonyl compounds to form methyl esters. In this case, it will insert a CH₂ group into the cyclobutanone structure, resulting in the formation of cyclopentanone (D).

**D = Cyclopentanone**

### Conclusion
The compound D is cyclopentanone.

### Summary of Steps:
1. Identify A as 1-butanol (C₄H₈O).
2. Convert A to B (cyclobutanol) using acid.
3. Oxidize B to C (cyclobutanone) using CrO₃ and acetic acid.
4. React C with diazomethane to form D (cyclopentanone).