ニトロイソオキサゾロンを前駆体とする多官能化合物の合成

抄録

4-Nitroisoxazolin-5 (2H) -ones 1 and 2 behave as excellent precursors for the syntheses of various kinds of polyfunctionalized compounds. Dianionic compounds, cyano-aci-nitroacetates 7 and dinitroglutaronitriles 9, are prepared from pyridinium salt 1 by the ring opening reaction and the succeeding condensation with ketones or aldehydes. When glutaronitriles 9 are treated with acetyl chloride, intramolecular ring transformation proceeds to afford polyfunctionalized isoxazoline 10 and isoxazoles 11. Further chemical transformation of 11 is possible, and leading to isoxazole derivatives 12-16. On the other hand, N-methylisoxazolone 2 is converted to functionalized units 17-19 upon treatment with amines or water. Polyfunctionalized pyrroles 23 are also prepared by the ring transformation of 2 with enolates of active methylene compounds.