Magnesiate-Utilized/Benzyne-Mediated Approach to Indenopyridones from 2-Pyridones: An Attempt To Synthesize the Indenopyridine Core of Haouamine.

An efficient, short-staged synthesis of -fused indeno[2,1-]- and indeno[1,2-]pyridin-2-ones, starting from 2-pyridones, using magnesiates of type RMgLi as nucleophilic and deprotonation agents, mediated by benzyne generated in situ, under optimized conditions, is described. Following the developed protocol, rare C4a-arylsubstituted indeno[2,1-]pyridones, resembling the core of haouamine, were obtained. The protocol offering the one-pot synthesis directly from 2-pyridone is also described.