Synthesis, Antimicrobial Evaluation, DFT, and Molecular Docking Studies of Pyrano [4,3-b] Pyranone and Pyrano[2,3-b]Pyridinone Systems.

Dehydroacetic acid (DHA) was utilized as a fundamental precursor in the synthesis of novel pyrano [4,3-b] pyran and pyrano [2,3-b] pyridine systems. Whereas, a new series of fused polyheteronuclear systems was achieved through the reaction of DHA with active methylene compounds such as malononitrile and pyrazolone. Whereas, the treatment of DHA 1 with cyclic ketones involving cyclohexanone and cyclododecanone afforded annulated tricyclic system 6 and spiro hybrid molecule 7. Also, the reaction of DHA 1 with cyanoacetamide derivatives 8 and 11 yielded their corresponding novel pyrano [2,3-b] pyridine-6-carbonitrile frameworks 9 and 12, respectively. Also, in silico predictive theoretical molecular docking studies for bioactive synthesized scaffolds against both HER2 and 6BBP displayed an optimistic result for compounds 2 b, 5, 9, and 12 highlighting their expediency as up-and-coming candidates for future preclinical trials. Additionally, all compounds were assessed as antibacterial agents against various types of four candidates of bacteria in the presence of ampicillin as a reference. Notably, compounds 6, 7, and 12 showed promising antibacterial potential against Bacillus subtilis with activity indexes (69.6, 91.3, and 82.6 %), respectively.