4,7-Epoxy-1H-isoindole-1,3(2H)-dione, hexahydro-3a,7a-dimethyl-, (3aalpha,4beta,7beta,7aalpha)- 76970-77-9 Cantharidin imide Hexahydro-3a,7a-dimethyl-4,7-epoxy-1H-isoindole-1,3(2H)-dione