Showing structure for (4e)-4-[2-(5,5,8a-trimethyl-2-methylidene-hexahydro-1h-naphthalen-1-yl)ethylidene]-5-oxooxolan-3-yl 4-(5,5,8a-trimethyl-2-methylidene-hexahydro-1h-naphthalen-1-yl)-2-(2-oxoethyl)but-2-enoate