Accession Number : AD0699069

Title :   PREPARATIVE CONVERSION OF OXIMES TO PARENT CARBONYL COMPOUNDS BY CERIUM(IV) OXIDATION,

Corporate Author : ROYAL MILITARY COLL OF CANADA KINGSTON (ONTARIO) DEPT OF CHEMISTRY AND CHEMICAL ENGINEERING

Personal Author(s) : Bird,J. W. ; Diaper,D. G. M.

Report Date : 12 AUG 1968

Pagination or Media Count : 7

Abstract : Oximes and semicarbazones are oxidized by ceric ammonium nitrate to the parent carbonyl compound in good yield. Suitable solvent systems include aqueous alcohols, acetonitrile, and acetic acid. The reaction is rapid at 0C or below. This procedure for regeneration of aldehydes and ketones from these derivatives may be preferable to the well-known hydrolytic procedures in some cases. The stoichiometry of the reaction was studied by isothermal calorimetry; two equivalents of oxidant are consumed by one mole of oxime evolving approximately 40 kcal/mole. A smaller consumption of oxidant by hexane-2,5-dione dioxime was attributed to stabilization of the monoxime as a nitroso chelate. Gaseous products were studied by infrared spectroscopy and nitrous oxide was identified as the sole product absorbing between 3 and 15 microns. A reaction mechanism is proposed involving one-electron oxidation to the iminoxy radical, oxidized by a second one-electron step to the alpha-hydroxy nitroso compound. Dimerization and elimination of hyponitrous acid gives the carbonyl compound. Nitrocyclohexane was absent from the oxidation product from cyclohexanone oxime. Carvone oxime was oxidized to carvone without racemization or significant attack of the olefin groups. (Author)

Descriptors :   (*CERIUM COMPOUNDS, *OXIDATION REDUCTION REACTIONS), (*OXIMES, *OXIDATION), ALDEHYDES, KETONES, CALORIMETRY, NITROSO COMPOUNDS, CANADA

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE