InChI=1/C15H15NO3/c1-19-13(17)11-7-4-5-9-15(11)10-6-2-3-8-12(10)16-14(15)18/h2-6,8,11H,7,9H2,1H3,(H,16,18 methyl 2'-oxo-1',2'-dihydrospiro[cyclohex-4-ene-1,3'-indole]-2-carboxylate spiro[cyclohex-4-ene-1,3'-[3H]indole]-2-carboxylic acid, 1',2'-dihydro-2'-oxo-, methyl ester