The first examples of chemical modification of oligomycin A

The first examples of chemical modification of antibiotic oligomycin A are described. The interaction of oligomycin A with hydroxylamine yielded six-membered nitrone annelated with the antibiotic at the positions 3,4,5,6,7. The reaction with 1-aminopyridinium iodide in pyridine led to pyrazolo[1,5-a]pyridine conjugated with the antibiotic at the positions 2 and 3 (product of addition to the C(2)-C(3) double bond followed by spontaneous oxidation). The structures of the compounds obtained were supported by NMR and mass spectrometry methods including the (15)N-labeling of compounds.