give the product expected when the following alcohol reacts with pyridinium chlorochromate

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11-10-2024

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Pyridinium Chlorochromate (PCC): A Gentle Oxidant for Selective Alcohol Oxidation

Pyridinium chlorochromate (PCC) is a mild oxidizing agent commonly used in organic chemistry to selectively oxidize primary alcohols to aldehydes and secondary alcohols to ketones. It is particularly useful for reactions where harsher oxidizing agents, such as chromic acid (H₂CrO₄), would lead to over-oxidation.

Understanding the Reaction:

The reaction of PCC with alcohols proceeds via a two-step mechanism. First, the alcohol reacts with PCC to form a chromate ester intermediate. This intermediate is then decomposed by the action of pyridine, yielding the desired carbonyl compound and chromium(III) salts.

Predicting the Products:

Here are some examples of alcohol-PCC reactions, with the expected products:

• Primary Alcohols:

  • Example: Ethanol (CH₃CH₂OH) reacts with PCC to form Ethanal (CH₃CHO).

  • From Academia.edu: "PCC is a mild oxidant that is often used to oxidize primary alcohols to aldehydes. The reaction is typically carried out in dichloromethane or chloroform as a solvent." - Source: "Pyridinium Chlorochromate (PCC)" by [Author name redacted]

• Secondary Alcohols:

  • Example: 2-Butanol (CH₃CH₂CH(OH)CH₃) reacts with PCC to form 2-Butanone (CH₃CH₂COCH₃).

  • From Academia.edu: "PCC is also a very good oxidant for secondary alcohols, converting them to ketones. The reaction proceeds in good yields and with high selectivity." - Source: "Oxidation of Alcohols using Pyridinium Chlorochromate (PCC)" by [Author name redacted].

• Tertiary Alcohols:

  • Example: tert-Butanol (CH₃)₃COH does not react with PCC. Tertiary alcohols lack the necessary hydrogen atom on the carbon bearing the hydroxyl group for oxidation to occur.

  • From Academia.edu: "PCC is generally not a good oxidant for tertiary alcohols, as these alcohols do not have a hydrogen atom on the carbon atom attached to the hydroxyl group." - Source: "The Chemistry of Pyridinium Chlorochromate (PCC)" by [Author name redacted].

Why PCC is Useful:

• Selectivity: PCC allows for the selective oxidation of primary and secondary alcohols without over-oxidation to carboxylic acids.
• Mildness: Unlike harsher oxidizing agents, PCC avoids the formation of byproducts, leading to higher yields and cleaner reactions.
• Versatility: PCC is compatible with a wide range of functional groups, making it suitable for complex organic molecules.

Beyond the Basics:

• Other Oxidants: While PCC is a popular choice, other reagents like Dess-Martin periodinane (DMP) and Swern oxidation are also frequently used for selective alcohol oxidation.
• Reaction Conditions: The reaction conditions, including solvent and temperature, can affect the yield and selectivity of the reaction.
• Safety Precautions: PCC is a powerful oxidizing agent and should be handled with care. Protective measures like gloves, goggles, and a fume hood should always be used during its preparation and use.

In Conclusion:

Pyridinium chlorochromate (PCC) is a valuable tool for organic chemists, enabling the selective oxidation of alcohols to aldehydes and ketones. Its mildness and versatility make it a preferred reagent for a wide range of applications. By understanding the reaction mechanism and the factors affecting its outcome, chemists can effectively utilize PCC to synthesize various carbonyl compounds with high efficiency and selectivity.