((3aR,4R,6Z,9S,10Z,11aR)-9-acetyloxy-6,10-dimethyl-3-methylidene-2-oxo-3a,4,5,8,9,11a-hexahydrocyclodeca(b)furan-4-yl) (E)-4-hydroxy-2-methylbut-2-enoate
((3ar,4r,6z,9s,10z,11ar)-9-acetyloxy-6,10-dimethyl-3-methylidene-2-oxo-3a,4,5,8,9,11a-hexahydrocyclodeca(b)furan-4-yl) (e)-4-hydroxy-2-methylbut-2-enoate