1H-1,5a-(iminomethano)cyclohepta[c][1,3]dioxolo[4,5-g][2]benzopyran-3-ol, 2,3,7,12b-tetrahydro- 2,3,7,12b-tetrahydro-1H-1,5a-(epiminomethano)cyclohepta[c][1,3]dioxolo[4,5-g]isochromen-3-ol InChI=1/C16H17NO4/c18-10-1-2-16-7-17-12(4-10)15(16)11-5-14-13(19-8-20-14)3-9(11)6-21-16/h1-3,5,10,12,15,17-18H,4,6-8H