The present invention describes a method which outlines a process for conversion of CBD to a Δ9-tetrahydrocannabinol (Δ9-THC) compound or derivative thereof involving treating a naturally produced CBD intermediate compound with an organoaluminum-based Lewis acid catalyst, under conditions effective to produce the Δ9-tetrahydrocannabinol compound or derivative thereof at a relatively high concentration. The source of the CBD is from industrial hemp having less than 0.3% Δ9-THC and extracting and purifying a CBD distillate or isolate or a combination thereof. This procedure will produce Δ9-THC that is essentially free from any other cannabinoids other than some trace amounts of the initial CBD starting material, or about 95% Δ9-THC and 2-4% CBD. Another aspect of the present invention relates to a process for further purification and enrichment of the Δ9-THC using distillation and collecting an essentially pure fraction of Δ9-THC using additional distillation or enrichment form of purification. Included are methods and processes to scale the reaction from the lab to large scale manufacturing. Included are methods for adding a molecule marker to authenticate high purity Δ9-THC products. Formulations and uses for pharmaceuticals, nutraceuticals, food products, and topicals are also provided.