So basically Rxn will not occur if solvents or Rxn mixture is too dry ?
He mentioned mass production method using HCl aq and heptane with molecular sieves before.
It seems like Hydro Chlorine can isomerise CBD into D9 under inert atmosphere and shall be the best acid for D9 selectivity.
This time he chose Aluminium Chloride for less-moisture.
AlCl3 will form HCL gas when exposed to the moisture (H2O).
Slight amount of H2O is needed to perform this reaction because it cannot release or form HCL inside Rxn.
the same logic, you can bubble dry HCL gas into CBD isolate dissolved in heptane or DCM, dried by Calcium Chloride.
Correct me, if my understanding were wrong.