Provide a synthesis of the following aldehyde starting from ethylene. Show the reagents and products for each step.
H2C=CH2 --> CH3-CH2-CH=O
Try to be as clear as possible. Thanks!
Two steps.
Add water across the double bond to make CH3CH2OH, then oxidize the alcohol to to aldehyde. You can read more about it here.http://www.chemguide.co.uk/organicprops/alcohols/oxidation.html
To synthesize the desired aldehyde (CH3-CH2-CH=O) starting from ethylene (H2C=CH2), you can follow a sequence of three steps. Here is a clear breakdown of each step, including the reagents and products involved:
Step 1: Hydration of ethylene to form ethanol (CH3-CH2-OH)
Reagents:
- Ethylene (H2C=CH2)
- Water (H2O)
- Acid catalyst, such as concentrated sulfuric acid (H2SO4)
Procedure:
1. In a reaction vessel, mix ethylene (H2C=CH2) with water (H2O) in the presence of an acid catalyst (H2SO4).
2. The acid catalyst helps in protonating the double bond in ethylene, creating an intermediate carbocation.
3. Water then attacks the carbocation, leading to the formation of ethanol (CH3-CH2-OH).
Step 2: Oxidation of ethanol (CH3-CH2-OH) to form ethanal (CH3-CH=O)
Reagents:
- Ethanol (CH3-CH2-OH)
- Oxidizing agent, such as pyridinium chlorochromate (PCC)
Procedure:
1. In a separate reaction, mix ethanol (CH3-CH2-OH) with an oxidizing agent, such as pyridinium chlorochromate (PCC).
2. The oxidizing agent selectively oxidizes the primary alcohol group in ethanol to an aldehyde group.
3. This reaction results in the formation of ethanal (CH3-CH=O).
Step 3: Reduction of ethanal (CH3-CH=O) to form the desired aldehyde (CH3-CH2-CH=O)
Reagents:
- Ethanal (CH3-CH=O)
- Reducing agent, such as sodium borohydride (NaBH4)
Procedure:
1. In another separate reaction, mix ethanal (CH3-CH=O) with a reducing agent, such as sodium borohydride (NaBH4).
2. The reducing agent donates a hydride ion (H-) to the carbonyl carbon of ethanal, reducing the carbonyl group to a primary alcohol group.
3. As a result, the desired aldehyde, CH3-CH2-CH=O, is formed.
By following these three steps, the aldehyde CH3-CH2-CH=O can be synthesized from ethylene (H2C=CH2).