Sciencemadness Discussion Board

Nucleophilic addition of halide to ketone

CrimpJiggler - 7-9-2011 at 02:53

Does aqueous HCl react with acetone to form 2-chloro-2-hydroxy-propane? Cl- is quite a strong nucleophile so I assume that it should add to the carbonyl carbon on in acetone and other non sterically hindered ketones but I can't find any info on hydrohalogenations of ketones. Is there something I'm not taking into consideration here?

[Edited on 7-9-2011 by CrimpJiggler]

ScienceSquirrel - 7-9-2011 at 05:31

Halide is also a very good leaving group and the competing reaction of eliminating hydrogen chloride is even more favourable than addition.
The major reaction is protonation to form the protonated ketone / enol, if a good electrophile like halogen is present you get alpha halogenation to form the extremely lacrymatory chloroacetone which is poor man's tear gas! :(