Synthesis of dispiro heteroanalogs of pyrrolizidine alkaloids: crystal and molecular structure of substituted 3',4'',5-trioxodispiro[(2'',5''-cyclohexadiene)-1''(4''H),7'-[7H]pyrrolizine-2'(3'H),2-[2H]pyrrole]-1'-carboxamide

Reactions of fused pyrrole-2,3-diones with binucleophiles

“…31,32 In 2014, the same group of authors 49 Konovalova et al hypothesised that the described reaction involved the initial addition of an activated β-CH group of 30 to the C 3a in molecule 1. This was then followed by closure of the pyrrole ring via an intramolecular attack by the NH group on the lactone carbonyl carbon atom C 4 in the oxazine ring and opening of the latter at C 4 -O 5 .…”