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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: aviad on November 15, 2014, 09:32:04 AM

Title: carboxylic acid with LDA
Post by: aviad on November 15, 2014, 09:32:04 AM
hi
i have a question when you react a carboxylic acid with LDA base will it take the proton to make the ion or the alpha proton im not sure due to the fact LDA fever the kinetic product 
the question itself is what is the proudect  of two aquvelant of hexanoic acid with 2 LDA and 1 etyil bromide
thank you.
Title: Re: carboxylic acid with LDA
Post by: orgopete on November 15, 2014, 10:45:06 AM
Why are they using two equivalents? Isn't that a clue?
Title: Re: carboxylic acid with LDA
Post by: asmcriminal on November 18, 2014, 10:25:13 PM
LDA attacks the beta hydrogen.
Title: Re: carboxylic acid with LDA
Post by: Altered State on November 19, 2014, 03:56:48 AM
Quote from: asmcriminal on November 18, 2014, 10:25:13 PM
LDA attacks the beta hydrogen.

Don't think so
It will start removing the -CO2H proton
Title: Re: carboxylic acid with LDA
Post by: asmcriminal on November 19, 2014, 09:56:17 AM
Quote from: Altered State on November 19, 2014, 03:56:48 AM
Quote from: asmcriminal on November 18, 2014, 10:25:13 PM
LDA attacks the beta hydrogen.

Don't think so
It will start removing the -CO2H proton

Yeah, i feel dumb, I don't know what i was thinking. Everything I said was wrong in my last post. But yeah, it will attack the H on the oxygen, that oxygen is resonance stabilized making it easier to deprotenate.
Title: Re: carboxylic acid with LDA
Post by: debabrata on December 10, 2014, 08:11:21 AM
shouldn't  2nd equivalent LDA attack alpha H after abstructing the carboxylic proton?