13793-48-1 1H-Isoindole-1,3(2H)-dione, 2-(tetrahydro-5,5-dimethyl-2-oxo-3-furanyl)- 2-(Tetrahydro-5,5-dimethyl-2-oxo-3-furanyl)-1H-isoindole-1,3(2H)-dione