3,6-methano-1H-benzo[3,4]cyclohepta[1,2-c]furan-1,5,7(3H,4H)-trione, 11-acetyloctahydro-9-(1-methylethenyl)-, (3S,6S,9S,11S)- Horiolide InChI=1/C19H22O5/c1-7(2)9-4-10-15-11-6-13(22)17(16(10)12(21)5-9)14(8(3)20)18(11)24-19(15)23/h9-11,14-18H,1,4-6H2,2-3H3/t9-,10?,11?,14-,15?,16?,17+,18-/m0/s rel-(3R,6R,9R,11R)-11-acetyl-9-isopropenyloctahydro-1H-3,6-methanobenzo[3,4]cyclohepta[1,2-c]furan-1,5,7(3H,4H)-trione