May 15, 2024, 02:26:23 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed  (Read 5416 times)

0 Members and 1 Guest are viewing this topic.

Offline wintermute

  • Regular Member
  • ***
  • Posts: 36
  • Mole Snacks: +2/-2
decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« on: January 17, 2007, 10:13:43 AM »
hi all,

i am puzzled with this transformation. can anybody provide me with the hint, please?

thanks in advance
Logged

Offline FeLiXe

  • Theoretical Biochemist
  • Chemist
  • Full Member
  • *
  • Posts: 462
  • Mole Snacks: +34/-7
  • Gender: Male
  • Excited?
    • Chemical Quantum Images
Re: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« Reply #1 on: January 17, 2007, 11:23:51 AM »
the start will probably be a deprotonation of the H that is alpha to three carbonyls because it is the most acidic one

Then you'll need a hydrogen shift and ethanol leaves (I guess)
Logged
Math and alcohol don't mix, so... please, don't drink and derive!

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« Reply #2 on: January 17, 2007, 12:40:49 PM »
Actually deprotonating the H between the three carbonyls won't get you anywhere (although you're right that it is the most acidic proton).  Think about using OH- as a nucleophile, or think about what else you have in solution that you could deprotonate.
Logged

Offline FeLiXe

  • Theoretical Biochemist
  • Chemist
  • Full Member
  • *
  • Posts: 462
  • Mole Snacks: +34/-7
  • Gender: Male
  • Excited?
    • Chemical Quantum Images
Re: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« Reply #3 on: January 17, 2007, 06:26:50 PM »
having fun using the "socratic way" ?  :)

how about this: reverse Claisen-condensation  8)
Logged
Math and alcohol don't mix, so... please, don't drink and derive!

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« Reply #4 on: January 17, 2007, 07:53:33 PM »
Quote from: FeLiXe on January 17, 2007, 06:26:50 PM
how about this: reverse Claisen-condensation  8)

There you go.
Logged

Offline wintermute

  • Regular Member
  • ***
  • Posts: 36
  • Mole Snacks: +2/-2
Re: decarbonylation of alpha-acetyl-beta-ketoester - mechanism needed
« Reply #5 on: January 18, 2007, 06:28:32 AM »
uf, it was there. just to see it :(
now, everything makes sense. ammonia was used to avoid competing ester hydrolysis....
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links