March 29, 2024, 09:49:33 AM
Forum Rules: Read This Before Posting


Topic: wittig?  (Read 2623 times)

0 Members and 1 Guest are viewing this topic.

Offline Ak

  • Regular Member
  • ***
  • Posts: 95
  • Mole Snacks: +8/-3
  • Gender: Male
  • "Man I am so juzzed" - Bart Simpson
wittig?
« on: August 18, 2008, 03:40:58 PM »
1. List the types of alkyl halides that can be used to prepare a triphenylphosphonium bromide and explain why only these halides are allowed.

ok so this question is talking about wittig preparation right? and if tht is correct then what i know is tht primary alkyl halides work best and secondary alkyl halides work but give poor yields.  I think aromatic halides also work well.  Is there anything that I'm missing, and did i understand the question.  Thanks

Offline azmanam

  • Chemist
  • Sr. Member
  • *
  • Posts: 1417
  • Mole Snacks: +160/-24
  • Mediocrity is a handrail -Charles Louis d'Secondat
Re: wittig?
« Reply #1 on: August 18, 2008, 04:08:29 PM »
Aromatic halides are not reactive enough to give a phosphonium salt.  I think you understand the question fine, but you haven't answered why. 

One thing, though.  'wittig preparation' is probably colloquially ok, but not a technical term.  We're preparing phosphonium salts, or perhaps 'Wittig salts', but we aren't forming phosphorus ylides.  It is the ylide that participates in the Wittig reaction.
Knowing why you got a question wrong is better than knowing that you got a question right.

Sponsored Links