[Cooper]

Hi,

Can anyone explain this mechanism? I have been trying to figure it out :s

Thanks

[Dan]

NaOH is a strong base.

To get started, what could it deprotonate?

[Cooper]

NaOH is a strong base.

To get started, what could it deprotonate?

It could deprotonate the alpha hydrogen, but how do you know it won't attack the carbonyl instead?

In general, how can you distinguish a base from a nucleophile?

[Dan]

It can and will do both. The key thing to remember is that both processes are reversible. Addition of hydroxide to the ketone is not productive. α-Deprotonation generates the enolate, which is nucleophilic. Can you see any electrophiles in your mixture?

[Cooper]

It can and will do both. The key thing to remember is that both processes are reversible. Addition of hydroxide to the ketone is not productive. α-Deprotonation generates the enolate, which is nucleophilic. Can you see any electrophiles in your mixture?

It could attack the chlorine molecule and break it heterolytically, right? It would form acyl chloride. Then would carbonyl addition-elimination occur? The OH could then attack the carbonyl carbon, the electrons in the double bond would go to the oxygen, then come back down and reform the pi bond, kicking out Cl.

Is that what happens?

[discodermolide]

Have a look here and see if it fits with your reaction.
http://en.wikipedia.org/wiki/Haloform_reaction

[Cooper]

Have a look here and see if it fits with your reaction.
http://en.wikipedia.org/wiki/Haloform_reaction

Yeah thanks, the reaction was a couple chapters ahead of where it was asked about in the book for some reason.