2,3-dimethyl-7-oxa-bicyclo[2.2.1]heptane-2exo,3exo-dicarboxylic acid anhydride, 7aalpha)-t, Kantaridin, 7aalpha)-bet, Canthari, 2,3-dimethyl anhydride, cantharides, Camptothecine, 2,3-dimethyl-7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid anhydride, Cantharidin, Cantharone, Kantharidin, Antharidin, 3a,7a-dimethyl-(3at,7at)-hexahydro-4r,7c-epioxido-isobenzofuran-1,3-dione, 4,7-Epoxyisobenzofuran-1,3-dione, hexahydro-3a,7a-dimethyl-, (3aα,4β,7β,7aα)-, 2endo,3endo-dimethyl-7-oxa-norbornane-2exo,3exo-dicarboxylic acid-anhydride