Synthesis of some 3-alkenyl-4-oxo-6,7-dihydro-4H-pyrano[3,4-d]isoxazoles

A series of 3-alkenyl-4-oxo-6,7-dihydro-4H-pyrano3,4-d]isoxazole derivatives was prepared by reaction of hydroxylamine with 4,5-dioxo-2,3,7,8-tetrahydro-4H,5H-pyrano4,3-b]pyran derivatives.