6H-benzo[b]naphtho[2,3-d]pyran-6-one 6H-naphtho[2,3-c]chromen-6-one InChI=1/C17H10O2/c18-17-15-10-12-6-2-1-5-11(12)9-14(15)13-7-3-4-8-16(13)19-17/h1-10