The reaction , `2RCHO overset("Al-ethoxide")(rarr) RCOOCH_(2)R` is called -

Options

A. Tischenko reaction
B. Knoevangel reacion
C. Cannizzaro reaction
D. HVZ reaction

Answer

To solve the question regarding the reaction `2RCHO overset("Al-ethoxide")(rarr) RCOOCH_(2)R`, we need to identify the name of the reaction. Let's break down the steps to arrive at the answer.

### Step 1: Identify the Reactants and Products
The reaction involves two molecules of an aldehyde (RCHO) reacting in the presence of aluminum ethoxide (Al-ethoxide) to produce an ester (RCOOCH2R).

**Hint:** Look at the structure of the reactants and products to understand the transformation occurring in the reaction.

### Step 2: Understand the Mechanism
In this reaction, one molecule of the aldehyde is oxidized to a carboxylic acid (RCOOH), while the other molecule is reduced to an alcohol (RCH2OH). These two products then undergo esterification, where water is eliminated to form the ester.

**Hint:** Consider how aldehydes can react under specific conditions to form different functional groups.

### Step 3: Identify the Name of the Reaction
The reaction described is known as the **Shenko reaction**. This reaction is characterized by the condensation of two aldehydes in the presence of a catalyst (like aluminum ethoxide) to form an ester.

**Hint:** Familiarize yourself with various organic reactions and their names to recognize them easily.

### Step 4: Eliminate Other Options
- **Novengel Reaction:** Involves aldehydes or ketones with active methylene groups, which is not applicable here.
- **Canizaro Reaction:** Involves aldehydes without alpha-hydrogens undergoing self-oxidation and reduction, which does not fit our case since RCHO has alpha-hydrogens.
- **HVZ Reaction:** Involves halogenation of carboxylic acids, irrelevant to the formation of esters from aldehydes.

**Hint:** Analyzing the characteristics of each reaction can help you eliminate incorrect options.

### Conclusion
The reaction `2RCHO overset("Al-ethoxide")(rarr) RCOOCH_(2)R` is called the **Shenko reaction**.