It looks like "THC" and "tetrahydrocannabinol" resolve to different isomers. One has wedges (stereo information) and they have different double bond positions (the double lines).
The problem here is naming compounds - a name like "THC" is not precise enough to distinguish between these isomers. A more exact name could be "(–)-trans-Δ⁹-tetrahydrocannabinol" (from wikipedia).
The problem here is naming compounds - a name like "THC" is not precise enough to distinguish between these isomers. A more exact name could be "(–)-trans-Δ⁹-tetrahydrocannabinol" (from wikipedia).