Showing structure for (3as,4s,4ar,7as,8s,9r,9as)-4a,8-dimethyl-9-[(3-methylbutanoyl)oxy]-3-methylidene-2,5-dioxo-3ah,4h,7ah,8h,9h,9ah-azuleno[6,5-b]furan-4-yl (2s)-2-methyloxirane-2-carboxylate