{"knowledge_schema": {"broad_category": "Chemistry \u2192 Organic Chemistry \u2192 Reaction Mechanisms", "refinement": "This problem involves the identification of a final product from a series of chemical reactions based on the starting compound's molecular formula and NMR data.", "specific_scope": "The focus is on the transformation of a compound with the molecular formula C8H9NO through diazotization, hydrolysis, and subsequent reactions with KOH under heat.", "goal": "Determine the final organic product resulting from the specified reactions and identify it from the given candidates."}, "summary": "This problem requires understanding organic chemistry reactions, specifically the transformation of a compound with the molecular formula C8H9NO through a series of reactions involving NaNO2, HCl, water, and KOH. The NMR data provides insight into the structure of the compound, which helps in identifying the final product after the reactions. The goal is to analyze the reactions and select the correct final product from the provided options, which is identified as 2,4-bis(4-hydroxyphenyl)but-2-enal."}