Methanol is not prepared by :

Options

A. Destructive distillation of wood
B. Catalytic hydrogenation of carbon monoxide
C. Catalytic oxidation of methane
D. Hydroboration-oxidation of ethylene

Answer

To determine which method does not produce methanol, let's analyze each option step by step.

### Step 1: Destructive Distillation of Wood
- **Process**: Wood is heated in the absence of air (destructive distillation) at temperatures between 450-550°C.
- **Products**: This process yields various products including pyrolytic oils, tar, and gases. One of the products can be methanol after further reactions with acetic acid and hydrolysis.
- **Conclusion**: Methanol can be produced by this method.

### Step 2: Catalytic Hydrogenation of Carbon Monoxide
- **Process**: Carbon monoxide (CO) is reacted with hydrogen (H2) in the presence of catalysts like ZnO, CrO2, and Cr2O3 at high temperatures (200-300°C).
- **Products**: This reaction produces methanol (CH3OH).
- **Conclusion**: Methanol can be produced by this method.

### Step 3: Catalytic Oxidation of Methane
- **Process**: Methane (CH4) is oxidized using oxygen (O2) in the presence of a copper catalyst at 573 K.
- **Products**: The reaction yields methanol (CH3OH).
- **Conclusion**: Methanol can be produced by this method.

### Step 4: Hydroboration of Ethylene
- **Process**: Ethylene (C2H4) is treated with diborane (B2H6) in a solvent like THF.
- **Products**: This reaction leads to the formation of an organoborane intermediate, which upon hydrolysis produces ethanol (C2H5OH), not methanol.
- **Conclusion**: Methanol is **not** produced by this method.

### Final Answer
The method that does not produce methanol is **Hydroboration of Ethylene**.

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