Converting primary alcohol to carboxylic acid

[reising1]

---

Members don't see this ad.

(sorry this is in the wrong forum but I don't know how to move it)

Examkrackers page 47 of 1001 Orgo questions has this question:

Which of the following will convert a primary alcohol to an carboxylic acid?
A. LiAlH5
B. dilute cold KMnO4
C. K2CrO4
D. O3 and (CH3)2S

The answer is C.

I had always thought that KMnO4 was the strongest oxidizing agent and is used for this purpose. Wikipedia seems to agree. So why is the answer C? Is it that oxidation needs hot temperature?

 

[Rhino1000]

I also was under the impression that KMnO4 is a strong oxidizing agent that would be suitable for this purpose.

 

[SSerenity]

You would need hot concentrated KMnO4. Its described as dilute & cold. This should be your red flag.

 

[reising1]

You would need hot concentrated KMnO4. Its described as dilute & cold. This should be your red flag.

That's just flat out picky...wow. Okay, well I'll add that to my flashcard.

So for oxidations, is heat needed only when using KMnO4?

 

[Vurday]

One more thing you can recognize is that K2CrO4 is a Cr (VI) Reagent
Cr (VI) are strong oxidizing agents and will oxidize alcohols all the way to carboxylic acids if they can

 

[rfvbnmju]

That's just flat out picky...wow. Okay, well I'll add that to my flashcard.

So for oxidations, is heat needed only when using KMnO4?

It's not really picky. Cold KMnO4 only goes to aldehyde. Hot concentrated goes to acid.

Sent from my SPH-M930 using Tapatalk 2