Oxidation reaction of primary alcohol to aldehyde and also carboxylic acid. Send a graphical explanation

Here is a graphical explanation of the oxidation of a primary alcohol to an aldehyde and then to a carboxylic acid:

$$\text{R-CH}_2\text{OH} \quad \xrightarrow{\text{Mild oxidizing agent (e.g., PCC)}} \quad \text{R-CHO} \quad \xrightarrow{\text{Strong oxidizing agent (e.g., K}_2\text{Cr}_2\text{O}_7\text{/H}^+)} \quad \text{R-COOH}$$

• Primary Alcohol to Aldehyde: A primary alcohol ($\text{R-CH}_2\text{OH}$) can be oxidized to an aldehyde ($\text{R-CHO}$) using a mild oxidizing agent. Examples include Pyridinium Chlorochromate (PCC) in dichloromethane. This reaction stops at the aldehyde stage because PCC is a selective oxidant and the reaction is often carried out under anhydrous conditions.

• Aldehyde to Carboxylic Acid: The aldehyde ($\text{R-CHO}$) can then be further oxidized to a carboxylic acid ($\text{R-COOH}$) using a strong oxidizing agent. Examples include potassium dichromate ($\text{K}_2\text{Cr}_2\text{O}_7$) in acidic conditions ($\text{H}^+$), potassium permanganate ($\text{KMnO}_4$), or chromic acid ($\text{CrO}_3/\text{H}_2\text{SO}_4$).

• Primary Alcohol to Carboxylic Acid (Direct): A primary alcohol can also be directly oxidized to a carboxylic acid using a strong oxidizing agent, bypassing the isolation of the aldehyde intermediate.