(13S,14S)-ent-3,12-Dioxo-8alpha,13;14,15-diepoxylabdane (3S,4aS,10aR)-3,4a,7,7,10a-pentamethyl-3-[(2S)-oxiran-2-yl]octahydro-1H-benzo[f]chromene-2,8(3H,4aH)-dione 1H-naphtho[2,1-b]pyran-2,8(3H,4aH)-dione, octahydro-3,4a,7,7,10a-pentamethyl-3-[(2S)-oxiranyl]-, (3S,4aS,10aR)- 3,4a,7,7,9,10a-Hexamethyl-3-oxiranyl-octahydro-benzo[f]chromene-2,8-dione InChI=1/C20H30O4/c1-17(2)12-6-9-19(4)13(18(12,3)8-7-14(17)21)10-15(22)20(5,24-19)16-11-23-16/h12-13,16H,6-11H2,1-5H3/t12?,13?,16-,18+,19-,20+/m0/s