CBD to THC isomerization: How important are anhydrous acids in this SOP?

Hello There!

I want to do a simple isomerization of CBD to THC.
The SOP has been mentioned a few times on this forum already:

Dissolve 1g of CBD in 10ml 0.005molar H2SO4 in glacial acetic acid.

I initially thought I can create the acid solution by adding 0.5 ml of 0.1 molar H2SO4 to 9.5 ml of glacial acetic acid.
Since a lot of other SOPs underline the importance of anhydrous acids, I was wondering if my solution mentioned above would work since my H2SO4 is only 0.1 molar so a bit of water would act as an ampholyte.

I am new to this and would appreciate every little help :slight_smile:
Thanks for your attention.


I’d suggest checking out ILL NYE CBD-D8 Conversion Master SOP

I don’t believe I’ve specifically seen an answer to your questions, but there are folks in there who can.


Not really the most Thc favorable acids for the task
If you insist on h2so4 I would add some NACL
Making hcl in the process an acid of wich we know give s decent results


Thank you very much for your answer!

I guess in this case I will use 30 %~ HCl (aq) and follow the formula from this paper:

I wasn’t aware that HCl produces better results than H2SO4, so again, thank you very much! :slight_smile: