Go Back   Student Doctor Network Forums > Pre-Medical Forums > MCAT Discussions > MCAT Study Question Q&A

Notices

MCAT Study Question Q&A Subforum specifically for asking questions when studying for the MCAT.
Please no actual MCAT questions.
RSS: Feed Icon


Reply
 
Thread Tools Display Modes
Old 05-01-2012, 08:28 PM   #1
Senior Member
 
Join Date: May 2009
Posts: 419
SDN 2+ Year Member
Default Grignards and carboxylic acids?


SDN Members don't see this ad. (About Ads)
I know that grigs can create carboxylic acids (grig +CO2)

But i was wondering what happens when it encounters a CA. Does it create a geminal diol? Or just snatch the H and become protonated?
johnwandering is offline   Reply With Quote
Old 05-01-2012, 08:30 PM   #2
Senior Member
 
Join Date: May 2009
Posts: 419
SDN 2+ Year Member
Default

Also, for grigs +esters
Why does grig knock off OR- but not the final OH-? I thought OR- had a much lower Pkb number than OH-
johnwandering is offline   Reply With Quote
Old 05-02-2012, 09:24 AM   #3
go nads go!
 
dmf2682's Avatar
 
Status: Pre-Medical
Join Date: May 2011
Posts: 1,309
Rocket Scientist
Default

the grignard makes a carboxylate in the first step, which is then protonated by acid in the second step. Second step only occurs after the grignard reagent is out of the picture.
dmf2682 is offline   Reply With Quote
Old 05-02-2012, 11:06 AM   #4
Senior Member
 
Join Date: Jul 2011
Posts: 315

Default

So, just like an amine attacking the carboxylic acid,

Grignard just takes the H off the Carboxylic acid...
hellocubed is offline   Reply With Quote
Old 05-03-2012, 02:03 PM   #5
8-16-13-39-42-45
 
gettheleadout's Avatar
 
Status: Pre-Medical
MDApps: View Profile
Join Date: Jun 2010
Posts: 8,917
SDN Moderator SDN Gold Donor SDN 2+ Year Member
Default

Quote:
Originally Posted by hellocubed View Post
So, just like an amine attacking the carboxylic acid,

Grignard just takes the H off the Carboxylic acid...
Which makes sense considering Grignards are basic enough to deprotonate alcohols.
__________________
Summer Research Data | Med School Info & Thread | Med School Data & Thread | SDN Mobile for iPhone/iPad or Android | Donate for perks!


MCAT Flashcard Count: 650
gettheleadout is offline   Reply With Quote

Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 05:30 AM.


Comments are closed.