Showing structure for (1s,2s,4ar,7r,8ar)-1-hydroxy-7-(3-methoxy-3-oxoprop-1-en-2-yl)-1,4a-dimethyl-6-oxo-hexahydro-2h-naphthalen-2-yl (2r,3r)-2,3-dimethyloxirane-2-carboxylate