InChI=1/C10H9NO5/c1-14-9(13)5-4-10(16-11-5)3-2-6(12)7-8(10)15-7/h2-3,7-8H,4H2,1H methyl 5'-oxo-4H-spiro[isoxazole-5,2'-[7]oxabicyclo[4.1.0]hept[3]ene]-3-carboxylate spiro[isoxazole-5(4H),2'-[7]oxabicyclo[4.1.0]hept[3]ene]-3-carboxylic acid, 5'-oxo-, methyl ester