Aj. Maroulis et al., THE LEAD-TETRAACETATE OXIDATION OF BISACYLHYDRAZONES OF ALPHA-DIKETONES - A SCOPE REASSESSMENT, Journal of heterocyclic chemistry, 30(4), 1993, pp. 913-916
Oxidation of the title compounds yields, besides the reported isoimide
s 3 and/or the amides 4, also the imides 5. The observed product dicho
tomy is considered as the result of an intramolecular nucleophilic att
ack on the aroyl group, of the pressumed zwitterionic intermediate 2,
by O or N present in the ambident N-aroylimine site of 2. The results
of AM1 calculations agree with the product studies and both permit the
formulation of a set of rules correlating structure and selectivity.