作者:Raymond C. F. Jones、Stephen H. Dunn、Kathryn A. M. Duller
DOI:10.1039/p19960001319
日期:——
Cycloaddition of oxygen-functionalized nitrile oxides to the enamine from ethyl acetoacetate produces 4-ethoxycarbonyl-5-methylisoxazoles carrying a 3-tetrahydropyranyloxymethyl, 3-diethoxymethyl or 3-ethoxycarbonyl substituent; the 3-formylisoxazole is prepared from the former two and condensed in situ with phosphoranes to give 3-alkenylisoxazoles that are cleaved by hexacarbonylmolybdenum or hydrogenolysis to afford alpha-alkoxycarbonyl-beta-diketones.