The unsaturated acyldiazabicyclic ketones (1 and 2) are converted by heating in methanol to the acylpyrrolinones and 6-acylamidopyridines. In aqueous base the acetyl ketone (1) and the methoxy ketone give the 4-aminopiperidines, respectively, which are readily converted to the pyridone. The benzoyl ketone (2) in aqueous base gives predominantely the enamino ketone. Mechanisms for these reactions and for the thermal conversion of 2 to the uretidine are proposed. Initial fragmentation of 1 and 2 is suggested to give the azetinone which is then attacked by water or methanol to give intermediates that undergo cyclizations or fragmentations. (Author)
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