December 05, 2021, 10:22:03 AM
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Topic: how can I obtain butanoic ac. from 1-propanol, is this even possible!?  (Read 11896 times)

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Offline etjusticepourtous

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I personally think that the professor is messing with us. I read a book, and looked everywhere in the internet, and I can't find a way to make this possible. I can can make propanoic ac. from the 1-propanol, but not butanoic ac.
The funny thing is that the professor hasn't explained nothing on how to go about these types of problems. What a jerk...

Offline Honclbrif

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How would you go about converting an alcohol to a carboxylic acid?
Individual results may vary

Offline etjusticepourtous

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By oxidation

CH3CH2CH2OH + KMnO4 ------------> CH3CH2-COOH

Can I do this?

CH3CH2CH2OH + CO ----------------> CH3CH2CH2-COOH

Thanks, I think I found the answer.

CH3CH2CH2OH + PBr3 ------>  CH3CH2CH2Br + Mg, ether + CO2 + H3O+ -----> CH3CH2CH2COOH



So let me see if I understand this, The OH leaves with all the electrons, and the CH2 has a positive charge, and then the Br attacks and bonds with the CH2 (halogen reaction).Then the Mg takes the Br, and the C02 takes its place (grignard reaction), and finally an H from the H3O+ joins the C00.(hydration reaction)
« Last Edit: August 12, 2011, 03:14:10 PM by etjusticepourtous »

Offline Doc Oc

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This synthesis is possible using reactions that are taught in undergraduate organic chemistry, I just don't know how far along in the series you are.  What was the last set of reactions that you learned?

Hint: You will need to convert propanol into a nucelophile at some point.

Offline etjusticepourtous

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the last thing we covered was cyanide addition

Offline Nosterius

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In the present situation, you would need to add 1 carbon atom to a propane unit. A cyanide addition would be a very wise choice indeed, as it is a very good nucleophile.

How would you do it from 1-propanol?


Offline etjusticepourtous

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In the present situation, you would need to add 1 carbon atom to a propane unit. A cyanide addition would be a very wise choice indeed, as it is a very good nucleophile.

How would you do it from 1-propanol?



I think is way easier with the Grignard reaction, but here it goes.

CH3CH2CH2OH + O -----> CH3CH2CHO + NaCN + H20 ---------> CH3CH2CHONaCN + H --------> CH3CH2CHOHCN + H/heat ---------> CH3CH2CHOHCOOH is not right, but i followed the example the teacher gave

Offline Guitarmaniac86

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In the present situation, you would need to add 1 carbon atom to a propane unit. A cyanide addition would be a very wise choice indeed, as it is a very good nucleophile.

How would you do it from 1-propanol?



I think is way easier with the Grignard reaction, but here it goes.

CH3CH2CH2OH + O -----> CH3CH2CHO + NaCN + H20 ---------> CH3CH2CHONaCN + H --------> CH3CH2CHOHCN + H/heat ---------> CH3CH2CHOHCOOH is not right, but i followed the example the teacher gave

Id convert 1-propanol to 1-bromopropane then react it with hydrogen cyanide under SN2 conditions and then react the 1-propanitrile with acid or base and heat it to the carboxylic acid...
Don't believe atoms, they make up everything!

Offline Doc Oc

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You can do it via cyanide addition, although you wouldn't want to use the aldehyde as the electrophile.

Following your suggestion to make a Grignard out of it, what electrophile could you use to extend the chain by 1 carbon and install something like a carboxylic acid?  (hint: it's a gas)

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