Tetrahydrocannabinol, along with its double bond isomers and their stereoisomers, is one of only three cannabinoids scheduled by the Convention on Psychotropic Substances (the other two are dimethylheptylpyran and parahexyl).ronabinol is the INN for a pure isomer of THC, (–)- trans -δ 9 -tetrahydrocannabinol, which is the main isomer found in cannabis.