There has been considerable research into the synthesis of THC and its analogues. A prominent figure in the early work in the 40's is Roger Adams. Many THC analogues have been synthesized, some with potencies (supposedly) 512 times that of the natural THC. The two areas on the structure that are the pharmacological functional groups are the long alkyl chain on the aromatic ring and variations on the nonaromatic ring. Acetylation of the hydroxyl usually produces a more potent compound. Look in the Merck Index under Nabilone, Synhexyl, tetrahydrocannabinol, cannabinol, and cannabidiol. This is a good start on cannabinoid chemistry, but there seem to be myriad articles on nitrogen analogues of all sorts and other heteroatoms like sulfur. Too many for me to mention all of the references. Another author worth mentioning is T. Petrzilka (don't ask me how to pronounce that...). (Helv. Chim Acta 52, 1102 (1969); 50, 719 (1967); 1416 (1967); 2111 (1967)) St. Anthony -- / N \ O I don't need God! | \ | || Ph All I need is an amoeba! | | |_O-C-C-OH \ / / Ph St. Anthony | aankrom@nyx.cs.du.edu