Showing structure for (3ar,4r,6ar,9ar,9br)-9-methyl-3,6-dimethylidene-2-oxo-3ah,4h,5h,6ah,7h,9ah,9bh-azuleno[4,5-b]furan-4-yl (2z)-2,4-dihydroxybut-2-enoate