Abstract
The reactions of kojic acid and its related γ-pyrones with anhydrous hydrazine have been investigated. Kojic acid and hydrazine gave 3, 6-dihydroxymethyl-4-oxo-l, 4-dihydro-pyridazine and 3-hydroxymethyl-pyrazolyl-(5)-glycoloyl-hydrazone, respectively, in 65% and 21% yields. The same reaction occured in the case of allomaltol and pyromeconic acid and gave the analogous results. On the other hand, 5-methoxykojic acid was allowed to react with hydrazine and afforded 1-amino-2-hydroxymethyl-5-methoxy-γ-pyridone and α[3-hydroxymethyl-pyrazolyl-(5)]-α-methoxy-acetaldehyde-hydrazone, respectively. The structural elucidation of these products could be fully substantiated by chemical evidences and spectroscopic data. The mechanisms for the reactions are also discussed.
