Some reactions of oximes and related topics.

Abstract

The thesis has been divided into four chapters:

Chapter 1 – Acid-Catalyzed Reactions of Oxime Derivatives Although vinylhydroxylamine derivatives (2) have been implicated as intermediates in the Wolff–Semmler aromatization reaction and other dehydrogenation sequences of oximes of unsaturated ketones, direct evidence for their involvement in simple ketoximes has been lacking. In this chapter, the preparation and reactions of isoxazol-5-ones (3), having the vinylhydroxylamine group “locked” in position, are described.

Chapter 2 – A New Reaction of Oximes A new reaction of ketoximes has been reported. A number of ketoximes (4), on treatment with a mixture of acetic anhydride, acetyl chloride, and pyridine, give the triacetate (5) – 2-O-acylenamino-1,1-diacyl derivative. Migration of the acyl group has been shown to be intramolecular.

Chapter 3 – A New and Novel Rearrangement of Cyclohexane-1,4-dione Dioxime in PPA Cyclohexane-1,4-dione dioxime in polyphosphoric acid (PPA) at 190?°C gave an unexpected rearrangement product: o-phenylenediamine. An attempt has been made to investigate the mechanism of this reaction using isotopically labelled dione dioximes.

Chapter 4 – Acid-Catalyzed Conversion of Cyclohexane-1,4-diones into Monohydric Phenols Cyclohexane-1,4-diones have been converted to monohydric phenols on boiling with aqueous concentrated HCl in good yields. A plausible mechanism has been postulated.