5,8-Dimethyl-3-methylene-3a,7,7a,8,9,9a-hexahydroazuleno[6,5-b]furan-2,6(3H,4H)-dione AIDS-140789 AIDS140789 NSC654208 {Azuleno[6,5-b]furan-2,6(3H,4H)-dione,} 3a,7,7a,8,9,9a-hexahydro-5, 8-dimethyl-3-methylene-