Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: eureka123 on October 27, 2009, 10:28:17 PM

Title: What is the final product ?
Post by: eureka123 on October 27, 2009, 10:28:17 PM

What is the final product ?

Title: Re: What is the final product ?
Post by: nj_bartel on October 28, 2009, 12:14:45 AM

What's LDA act as?

Title: Re: What is the final product ?
Post by: orgoclear on October 28, 2009, 03:10:45 AM

LDA is a hindered strong base. So basically you have to decide where it will attack i.e. which acidic H it will remove to form the carbanion.

Title: Re: What is the final product ?
Post by: eureka123 on October 28, 2009, 07:21:56 AM

oh...i know all that ...i have doubts regarding final product....

i am posting two options..tell me which it will be ???

Title: Re: What is the final product ?
Post by: nj_bartel on October 28, 2009, 08:03:07 AM

Are alkyl chains electron donating or withdrawing?

Title: Re: What is the final product ?
Post by: eureka123 on October 28, 2009, 08:07:49 AM

electron donating..

plz tell me the final answer....

Title: Re: What is the final product ?
Post by: Dan on October 28, 2009, 08:33:10 AM

Remember, you only have 1 eq of LDA, you can only deprotonate your starting material once

Title: Re: What is the final product ?
Post by: nj_bartel on October 28, 2009, 11:07:14 AM

Unless your product has a more acidic proton than your reagant.  Is that the case?

Title: Re: What is the final product ?
Post by: eureka123 on October 28, 2009, 01:07:41 PM

thats what my doubt is....

plz all the experts here reply...

i feel ans should be 2nd option..but ans given in book is 1st option

Title: Re: What is the final product ?
Post by: nj_bartel on October 28, 2009, 02:01:29 PM

Well I'd say you're right and the book is wrong.

Title: Re: What is the final product ?
Post by: lavoisier on October 28, 2009, 02:22:21 PM

I agree.
It might be a typo in your book.

However, even if some dialkylated material were formed, it would be in mixture with some monoalkylated material.
Unless we think that a rather hindered 1,3-dicarbonyl compound is allylated by an excess of allyl bromide without any base? I don't think so.

Title: Re: What is the final product ?
Post by: eureka123 on October 28, 2009, 09:59:34 PM

Thanx everyone

but

Quote from: nj_bartel on October 28, 2009, 11:07:14 AM

Unless your product has a more acidic proton than your reagant.  Is that the case?

plz explain why the above situtation with an example if possible

Title: Re: What is the final product ?
Post by: nj_bartel on October 28, 2009, 10:52:37 PM

If trifluoromethane was your substituent, that would increase the acidity of the remaining proton.

Title: Re: What is the final product ?
Post by: eureka123 on October 29, 2009, 02:14:10 AM

ok ..tahnx everyone for your contributions...
such thpe of sicussion help a lot  :) :)