The structure of the product(Z) in the reactions given below
`HC-=CH underset(H^+)overset(NaNH_2.CH_3COCH_3)to X underset(H_2O)overset(Hg^(2+), H_3O^(+)) to ` Z is

Options

A. `CH_3-CH_2-CH_2-oversetoverset(O)(||)C-CH_2OH`
B. `CH_3-undersetunderset(O)(||)C-oversetoverset(CH_3)|CH-CH_2OH`
C. `CH_3-undersetunderset(O)(||)C-undersetunderset(OH)(|)oversetoverset(CH_3)(|)C-CH_3`
D. `CH_3-CHOH-oversetoverset(CH_3)|CH-CHO`

Answer

To solve the problem step by step, we will analyze the reactions given and derive the structure of the product Z.

### Step 1: Identify the starting material
The starting material is an alkyne, specifically acetylene (HC≡CH).

### Step 2: Reaction with NaNH2
In the first step, acetylene reacts with sodium amide (NaNH2). Sodium amide is a strong base and will deprotonate the terminal hydrogen of acetylene, forming an acetylide ion (HC≡C⁻).

**Hint:** Remember that NaNH2 acts as a strong base and removes acidic protons from terminal alkynes.

### Step 3: Nucleophilic attack on the ketone
The acetylide ion (HC≡C⁻) acts as a nucleophile and attacks the carbonyl carbon of the ketone (CH3COCH3). This results in the formation of a new carbon-carbon bond and leads to the formation of an alkoxide intermediate.

The structure of the intermediate can be represented as:
- CH3-C(=O)⁻-C≡C-H

**Hint:** The nucleophile (acetylide ion) attacks the electrophilic carbon of the carbonyl group.

### Step 4: Protonation of the alkoxide
Next, we add H⁺ to the reaction mixture. The alkoxide ion (O⁻) will be protonated to form an alcohol. The structure now becomes:
- CH3-C(OH)-C≡C-H

**Hint:** Protonation of the alkoxide leads to the formation of an alcohol.

### Step 5: Hydration of the alkyne
In the next step, we perform hydration using Hg²⁺ and H3O⁺. The alkyne undergoes a hydration reaction, which involves the formation of a mercurinium ion. This step leads to the formation of a more stable carbocation.

**Hint:** The presence of Hg²⁺ facilitates the formation of a more stable carbocation during the hydration of the alkyne.

### Step 6: Formation of the ketone
Water attacks the carbocation, leading to the formation of a double bond and resulting in a ketone. The final product Z is:
- CH3-C(=O)-C≡C-H

This structure represents a ketone formed from the hydration of the alkyne.

### Final Answer
The structure of product Z is CH3C(=O)C≡CH.

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