63-Pyrroline, disproportionation

The hydroxamic acid function in most alicyclic and aromatic compounds is stable to hot dilute acid or alkali, and derivatives cannot undergo normal base-catalyzed Lessen rearrangement. Di Maio and Tardella," however, have shown that some alicyclic hydroxamic acids when treated with polyphosphoric acid (PPA) at 176°-195° undergo loss of CO, CO.2, or H2O, in a series of reactions which must involve earlj fission of the N—0 bond, presumably in a phosphoryl-ated intermediate. Thus, l-hydroxy-2- piperidone(108) gave carbon monoxide, 1-pyrroline (119), and the lactams (120 and 121). The saturated lactam is believed to be derived from disproportionation of the unsaturated lactam. 

Diphenyl-2-pyrroline, 27, 33 Diphenyl selenide, 24, 91 Diphenylthiocarb azide, 25, 38 Diphenylthiocarbazone, 25, 38 Dl- -PROPYI.AMINOETIIYI.AMINE, 23, 24 y-Di-n-propylaminopropylamine, 24, 46 Disproportionation, of diphenylthio-... 

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