RAPID AND SELECTIVE REGENERATION OF CARBONYL COMPOUNDS FROM THEIR OXIMES UNDER MILD. NEUTRAL AND SOLVENT-FREE CONDITIONS

The development of efficient and mild methods for the selective cleavage of C=N containing derivatives to afford carbonyl compound continues to be a significant aspect of experimental organic chemistry.' Oximes are extensively used for purification and characterization of carbonyl compounds and in the preparation of amides viu the Beckmann rearrangement. Their synthesis from non-carbonyl compounds' provides potential alternative pathway to aldehydes and ketones, if selective cleavage can be worked out. The important role of oximes as protecting groups4 owing to their hydrolytic stability has inspired the development of newer deoximation reagents such as Raney nickel,'a cetyltrimethylammonium permanganate,'h Dowex-50,5' ultrasonically stimulated baker's yeast,'" iron (111) perchlorate,5e zirconium sulfophenyl phosphate,5' ammonium persulfatesilica gel'g and manganese triacetate.5'1 The use of dimethyl dioxiraneha and silica supported peiiodateh" is restricted to ketoximes whereas pyridium chloroformate H20,,hC' ozonehd and TBHPx suffer from the disadvantage of over oxidation of ensuing aldehydes. Only a limited number of methods are thus available for this cleavage under mild reaction conditions.sh. ha.hd We now report a remarkably rapid deoximation reaction under mild, neutral and solvent-free conditions (Scheme).