Name the following reaction.
`PhCHO+CH_(2)(COOEt)_(2)overset((i) "Pyridine")underset({:((ii)H_(2)O),((iii) Delta","-CO_(2)):})toPh-CH-=CHCOOH`

Options

A. Perkin reaction
B. Aldol condensation
C. Claisen reaction
D. Knoevenagel

Answer

To name the reaction given in the question, we will analyze the components and the conditions under which the reaction occurs.

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in the reaction are benzaldehyde (PhCHO) and diethyl malonate (CH₂(COOEt)₂). Benzaldehyde is an aromatic aldehyde, and diethyl malonate contains an active methylene group.

2. **Identify the Conditions**: The reaction occurs in the presence of pyridine, which acts as a weak base, and water is also involved in the reaction. The reaction is followed by heating (indicated by Δ) and the release of carbon dioxide (CO₂).

3. **Analyze the Reaction Type**:
- The reaction involves an aromatic aldehyde (benzaldehyde) and an ester (diethyl malonate).
- The presence of an active methylene group (the methylene group between two carbonyls in diethyl malonate) is crucial for the reaction to proceed.
- The reaction does not involve any alpha hydrogen from the benzaldehyde since it does not have any.

4. **Determine the Name of the Reaction**:
- This reaction fits the criteria of the **Noyori Reaction** (also known as the Noyori Aldol Reaction or Noyori Condensation). In the Noyori reaction, an aldehyde or ketone with no alpha hydrogen reacts with a compound containing an active methylene group in the presence of a weak base to form an unsaturated carboxylic acid.

5. **Final Product**: The product formed is an unsaturated carboxylic acid (Ph-CH=CHCOOH), confirming that the reaction is indeed a condensation reaction leading to the formation of an unsaturated acid.

### Conclusion:
The name of the reaction is the **Noyori Reaction**.

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