(-)-Xylocarpin

(-)-2-(Acetyloxy)-8-(furan-3-yl)dodecahydro-3,3,5,7a-tetramethyl-10,13-dioxo-1,5-methano-2H,8H-oxireno[1,8]cycloocta[1,2-f][2]benzopyran-4-acetic acid methyl ester