billybaker - 18-12-2011 at 07:14
I just have a couple of questions. Is there a general guideline for the changes in a ketone when it is formed into an oxime. Or perhaps could you
start with an amine in mind and work backwards to discover the oxime and ketone?
kavu - 18-12-2011 at 08:09
Oxime formation starts off with a nucleophilic attack of hydroxylamine to the carbonyl carbon of the ketone. Reactions after this involve proton
transfers and then elimination of water. These steps are more or less fast when compared to the attack. Electron withdrawing groups make the carbonyl
carbon more prone to attack whereas bulky and conjugation prone groups disfavour the attack. These are more or less common characteristics for most
nucleophilic additions to a carbonyl group.
A detailed mechanism for oxime formation can be found (for example) at http://www.cf.edu/departments/instruction/las/science/chemis...