An alternative approach to the synthesis of 5<italic>H</italic>-chromeno[4,3-<italic>b</italic>]pyridin-5-one system using the cleavage of 5<italic>H</italic>,9<italic>H</italic>-pyrano[2',3':5,6]chromeno[4,3-<italic>b</italic>]pyridine-5,9-diones with binucleophiles

<graphic></graphic>Hantzsch reaction has been successfully employed for a one-step assembling of pyranopyridine fragment to produce 5<italic>Н</italic>,9<italic>Н</italic>-pyrano[2',3':5,6]- chromeno[4,3-<italic>b</italic>]pyridine-5,9-diones which upon treatment with binucleophiles undergo chemoselective γ-pyrone ring opening with the concomitant recyclization to give five-membered cycles, providing a concise route to 6-pyrazolyl(isoxazolyl)-5<italic>H</italic>-chromeno[4,3-<italic>b</italic>]- pyridin-5-ones. [ABSTRACT FROM AUTHOR]