Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Ak on August 18, 2008, 03:40:58 PM
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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
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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.