Thermal isomerization of CBC(an) to THC(an) [nonaromatic analogues of plant cannabinoids cannabichromene (CBC) and Delta(1)-tetrahydrocannabinol (THC), respectively] is predicted in silico and demonstrated experimentally. Density functional theory calculations support a similar isomerization mechanism for the corresponding plant cannabinoids. Docking studies suggest that THC(an), although nonaromatic, has a CB(1) receptor binding affinity similar to that of natural THC.