Biomimetic Cannabinoid Synthesis Revisited: Batch and Flow All-Catalytic Synthesis of (±)-ortho -Tetrahydrocannabinols and Analogues from Natural Feedstocks

Ultrasonic or Microwave Modified Continuous Flow Chemistry for the Synthesis of Tetrahydrocannabinol: Observing Effects of Various Solvents and Acids

Synthesizing tetrahydrocannabinol is a lengthy process with minimal yields and little applicability on an industrial scale. To close the gap between bench chemistry and industry process chemistry, this paper introduces a small-scale flow chemistry method that utilizes a microwave or ultrasonic medium to produce major tetrahydrocannabinol isomers. This process produces excellent yields and minimal side products, which leads to more efficient large-scale production of the desired cannabinoids.

Synthesis and Evaluation of Natural and Unnatural Tetrahydrocannabiorcol for Its Potential Use in Neuropathologies

(-)-trans-Δ9-Tetrahydrocannabinol (trans-(-)-Δ9-THC) has shown neuroprotective potential, but its medicinal benefits are not fully exploited due to the limitations of psychoactive properties. The lower homologues are non-psychoactive in nature but lack comprehensive scientific validation regarding neuroprotective potential. The present study describes the synthesis of non-psychoactive lower homologues of THC-type compounds and their neuroprotective potential. Both natural tetrahydro-cannabiorcol (trans-(-)-Δ9-THCO) and unnatural Δ9-tetrahydrocannabiorcol (trans-(+)-Δ9-THCO) were successfully synthesized starting from R-limonene and S-limonene, respectively, and investigated for neuroprotective potential in cellular models. The structures of both enantiomers were confirmed by NMR, HMBC, HQSC, NOESY, and COSY experiments. Results indicated that both enantiomers were nontoxic to the cells treated up to 50 μM. Neuroprotective properties of the enantiomers showed that treatments could significantly reverse the corticosterone-induced toxicity in SH-SY5Y cells and simultaneously cause elevated expression of brain-derived neurotrophic factor (BDNF). It was also observed that unnatural trans-(+)-Δ9-THCO displayed better activity than the natural enantiomer and can be further explored for its potential use in neuropathological ailments.

Continuous flow technology-a tool for safer oxidation chemistry

The advantages and benefits of continuous flow technology for oxidation chemistry have been illustrated in tube reactors, micro-channel reactors, tube-in-tube reactors and micro-packed bed reactors in the presence of various oxidants.

A review on the syntheses of Dronabinol and Epidiolex as classical cannabinoids with various biological activities including those against SARS-COV2

The very important psychoactive phytocannabinoid from Cannabis Δ⁹ tetrahydrocannabinol (Δ⁹-THC) and its non-psychotropic member is cannabidiol (CBD). These compounds have a variety of pharmacological activities. THC has been approved for the treatment of nausea caused by chemotherapy, multiple sclerosis and chronic and neuropathic pain and research is underway to use it to treat stimulation of dementia, anorexia nervous and Tourette’s syndrome. CBD has therapeutic benefits in Epilepsy, neuroprotective, cancer, inflammatory and anxiety. Recognizing candidate drugs efficiently in the new SARS-CoV2 disease 2019 (Covid-19) is crucial. Cannabidiol and Δ⁹-tetrahydrocannabinol have immunomodulatory and anti-inflammatory effects. They can reduce the uncontrolled cytokine production of acute lung injury. Although THD and CBD can be extracted from natural sources due to the disadvantages of this method such as difficulty in purification, cultivation, etc. It has been proven that chemical-synthesis methods of these two compounds can solve these problems. This review briefly summarizes the chemical-synthetic strategies of Dronabinol and Epidiolex from THC and CBD.

One-flow synthesis of tetrahydrocannabinol and cannabidiol using homo- and heterogeneous Lewis acids

Continuous flow chemistry holds great potential for the production of biologically relevant molecules. Herein, we present an approach for the continuous synthesis of cannabidiol and tetrahydrocannabinol in a one-flow system. The designed route consists of a reaction cascade involving Friedel-Crafts alkylation, subsequent ring opening and cyclisation in up to 45% yield. The reactions were successfully performed using both hetero- and homogeneous Lewis acids in continuous flow and provide yields that are similar to comparable batch processes.

Graphical abstract

Synthetic pathways to tetrahydrocannabinol (THC): an overview

The therapeutic effects of molecules produced by the plant species Cannabis sativa have since their discovery captured the interest of scientists and society, and have spurred the development of a multidisciplinary scientific field with contributions from biologists, medical specialists and chemists. Decades after the first isolation of some of the most bioactive tetrahydrocannabinols, current research is mostly dedicated to exploiting the chemical versatility of this relevant compound class with regard to its therapeutic potential. This review will primarily focus on synthetic pathways utilised for the synthesis of tetrahydrocannabinols and derivatives thereof, including chiral pool-based and asymmetric chemo- and biocatalytic approaches.

Synthesis of Cannabinoids: "In Water" and "On Water" Approaches: Influence of SDS Micelles

We have proven that the biomimetic-like synthesis of cannabinoids from citral and the corresponding phenolic counterpart may well be carried out using water as a solvent. The influence of different additives such as surfactants was also analyzed. Rationalization of the reaction mode and regiochemistry of the processes were provided in terms of “on water” and “in water” reactions. The same reactions were conducted in organic media using Ga(III) salts as catalysts. Worthy of being underlined, an unprecedented formal [2+2+2] process was found to occur between two citral molecules and the corresponding phenolic species in both aqueous and organic environments. Computational studies were performed in order to gain a comprehensive mechanistic and energetic understanding of the different steps of this singular process. Finally, the influence of SDS micelles in the chemical behavior of olivetol and citral was also pursued using PGSE diffusion and NOESY NMR studies. These data permitted to tentatively propose the existence of a mixed micelle between olivetol and SDS assemblies.