reduction of a carboxylic acid - please help!

[premd]

If you use LiAlH4 to reduce a carboxylic acid, don't you end up with a primary alcohol? According to one problem from Kaplan, you will end up with a diol (basically, a hydroxyl replaces the carbonyl part of the carboxylic acid).

---

Members don't see this ad.

 

[roycer]

I'm quite sure if you're reducing a carboxylic acid with just LiAlH4, you will end up with a primary alcohol.

 

[sehnsucht]

If you use LiAlH4 to reduce a carboxylic acid, don't you end up with a primary alcohol? According to one problem from Kaplan, you will end up with a diol (basically, a hydroxyl replaces the carbonyl part of the carboxylic acid).

thats odd.

 

[mrmilad]

There is a diol intermediate but the final product is a primary alcohol.

 

[axp107]

Doesn't NaBH4 give you a diol?

while

LiAlH4 gives you an alcohol?

 

[roycer]

NaBH4 reduces aldehydes and ketones to alcohols.

 

[amar21]

LiALH4 will reduce a carboxylic acid to a primary alcohol.

NaBH4 will reduce an aldehyde/ketone to a primary alcohol.

just know that! I'm not sure where kaplan got off saying it stops at a diol, but LiAlH4 is a very strong reducer and will proceed to completion. I just looked over my kaplan comprehensive review book for ths particular section and it does not mention anythinga bout a diol... all it says is "carboxylic acids are reduced by lithium aluminum hydride to the corresponding alcohols"..

I think the example that was given to you must have contained 2 -COOH groups within the structure... remember that LiAlH4 will reduce them both .. and as a result produce 2 -OH's.

 

[axp107]

I remember since NABH4 is weaker...

reduces the double bond of the carbonyl group only... meaning it adds 2 Hs, 1 to the OH and the other to the C.

 

[BBates25]

The final product will be a primary alcohol.

 

[sv3a]

LiAlH4 will always give a primary alcohol for carboxylic acids, aldehydes, and esters. It'll give a secondary alcohol for ketones and epoxides. I don't think there is any diol intermediate with reducing a carboxylic acid. Also, I'm pretty sure sodium borohydride is too weak to even touch carboxylic acids (it'll reduce aldehydes/ketones, though).