DEOXYGENATION REACTIONS OF AMINE OXIDES AND SULFOXIDES.
Abstract
The objective of this research was to determine the scope and nature of the reactions of pyridine N-oxide with electrophiles. A second purpose became the study of the reaction of dimethylsulfoxide with epoxides. A new synthesis of alpha-hydroxyaldehydes and ketones was discovered. It involves the oxidation of epoxides by dimethylsulfoxide, which is used as solvent. The discovery of the oxidation of carboxylic acids by pyridine N-oxides to form aldehydes and ketones led to the enunciation of a new mechanistic concept involving activation of carboxylic acids (by pyridine N-oxide) toward nucleophilic attack at the alpha-position. Side products of this novel 4-electron decarboxylative oxidation, when phenylacetic acid is used, are diphenylmaleic anhydride, mandelic acid acetate and phenylglyoxylic acid. Evidence was adduced that the currently accepted radical-pair mechanism for the production of esters in the reaction of acetic anhydride with 2- and 4-picoline N-oxide is probably incorrect. Although the attempted oxidation of naphthoquinone with pyridine N-oxide was apparently unsuccessful, interesting results have evolved out of a study of the structure and unusual physical properties of the 'hydrazone' of this dehydrodimer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1965
- Accession Number
- AD0625414
Entities
People
- Theodore A Cohen
Organizations
- University of Pittsburgh