4,16-Diacetyl-3-isobutyrylveracevin 4,9-Epoxycevane-3-beta,4-beta,12,14,16-beta,17,20-heptol 4,16-diacetate 3-isobutyrate Cevane-3-beta,4-beta,12,14,16-beta,17,20-heptol, 4,9-epoxy-, 4,16-diacetate 3-isobutyrate FL4916500