Which of the following compounds would be the main product of an aldol condensation of acetaldehyde and acetone ?

Options

A. `CH_(3)CH=CH*CHO`
B. `CH_(3)CH=CHCOCH_(3)`
C. `(CH_(3))_(2)C=CH*CHO`
D. `(CH_(3))_(2)C=CHCOCH_(3)`

Explanation

To determine the main product of an aldol condensation between acetaldehyde and acetone, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this case are:
- Acetaldehyde (CH₃CHO)
- Acetone (CH₃COCH₃)

### Step 2: Understand the Aldol Condensation Process
Aldol condensation involves two main steps:
1. Formation of an enolate ion from one of the carbonyl compounds.
2. Nucleophilic attack of the enolate on the carbonyl carbon of the other compound, followed by dehydration to form an α,β-unsaturated carbonyl compound.

### Step 3: Formation of the Enolate Ion
In this reaction, acetone (which has more alpha hydrogens) will form the enolate ion. The enolate ion is formed by deprotonation of the alpha hydrogen in acetone using a base (like NaOH).

- Enolate ion from acetone:
\[ CH₃C(=O)CH₃ \rightarrow CH₂=C(OH)CH₃ \]

### Step 4: Nucleophilic Attack
The enolate ion will act as a nucleophile and attack the carbonyl carbon of acetaldehyde:
- The carbonyl carbon of acetaldehyde is electrophilic due to the presence of the oxygen atom.

The reaction can be represented as:
\[ CH₂=C(OH)CH₃ + CH₃CHO \rightarrow \text{Aldol product} \]

### Step 5: Formation of the Aldol Product
After the nucleophilic attack, we will have a β-hydroxy aldehyde:
\[ CH₃C(OH)(CH₂CHO)CH₃ \]

### Step 6: Dehydration to Form the Final Product
The β-hydroxy aldehyde will undergo dehydration (loss of water) to form the final product, which is an α,β-unsaturated carbonyl compound:
\[ CH₃C=CHCOCH₃ \]

### Step 7: Identify the Main Product
The final product of the aldol condensation between acetaldehyde and acetone is:
\[ CH₃C(=CH)C(=O)CH₃ \]
This compound is a conjugated system and is stable.

### Conclusion
The main product of the aldol condensation of acetaldehyde and acetone is:
\[ \text{Option B: } CH₃C(=CH)C(=O)CH₃ \]

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