Why is easier to separate D9THCA of D8THCA than to separate D8 from D9

Why is it easier? I know how difficult is to separate the neutral forms but someone said that carboxylation of THC would solve the purification/separation matter.

I don’t know how.

Thank you very much!

It would be easier to separate D8THC (neutral) from D9THCa (acid) because they drop off most chromatography columns well apart and could be collected separately.

D8THCa (acid) from D9THCa (acid)… not sure the separation on those… might be pretty close and not doable.


That’s what I tough, but may be I was missing something…
Thank you!!

It would be interesting to see if D8thca decarbs at a different rate then d9thca

partial decarb followed by chroma could solve this, OR decarbing with a salt might be able to isomerize the d9thca into cbn and d8 making compliant d8

someone should try this, ive posted the paper with the table with what salts to use


I’m not saying that it is easier, but it certainly has way higher potential of being relatively easy to separate.

The neutral and non-crystalline cannabinoids are notoriously difficult to separate by distillation while only a very minute change in molecular structure between two crystalline compounds can have a drastic effect on crystallinity and crystal structure.


I would expect them to show slight differences in solubilities in alkanes, which could be exploited to separate them by iterative recrystalization. :thinking:


Yall ever throw some d8 into hte and just let it sit there?

What I noticed is the d8 will saturate the mother liquor and crash out the remaining thca

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Is it though? I think an answer to this question is THCa probably falls under the category of “D9”. THCa, having different solubility characteristics than d9 or d8 without the carboxylate group is why it’s easier to separate.

It’s capable of forming a crystal from a saturated solution, where decarbed d9 or d8 cant.

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What is iterative recristalization?
Becouse you are talking about separate the two acid forms right?
as @mitokid has pointed…
This is the interesting thing, I don’t see a situation where you have to separate an acid form from a neural form.
The interesting point is do it after carboxylation if this gives any benefit to separate or once isomerized from cbda.

If you’re aiming for THCa-B and you have a mixture of THCa-A and -B, then you can selectively decarboxylate THCa-A to THC and you’d be left with THC and THCa-B.

Separation of those two compounds is straightforward.

This is how I think Mechoulam’s group ended up with the THCa-B that was studied by X-ray crystallography in the 70s, I think it was.