Carboxylation - Adding the "a" back to THC


@DrJosh I asked explicitly if this was

  1. a trick you had performed?
  2. a trick you taught others?
  3. worth the effort?
  4. worth the price of admission.

the above response suggests it’s NOT something you’ve actually done before. I don’t have a problem with that part…so far nobody proposing recarboxylation here has.

however, your initial statement implies more intimate knowledge of the synthesis than your second.

with 30 years of synthetic chemistry behind you, it is not unreasonable that you could be fairly sure a synthetic route was available without having actually performed the synthesis.

However, when someone explicitly asks if you’ve done this before, it’s not a brilliant idea in a forum like this to ignore that question (it speaks to credibility).

You then give a vague, hand waving description, of how it might be achieved. The functional groups you refer to have names. use them. the required synthetic reactions have names. use them. the tools required have names. etc…not doing so brings the claim of 30 years playing this game into question. you see that right?

IF you were selling/teaching this technique, keeping exact details to yourself would certainly be appropriate. Which is why I asked it that was the case.

Because you didn’t respond, the reader is required to guess. My guess is that you haven’t done it. Don’t sell it. And couldn’t perform the trick today without additional reading or R&D. Others are making even less charitable guesses. based on what you have, and have not said.

currently your “me too” post ads little to the discussion…and imo diminishes your credibility. which seems counter productive for a vendor or consultant.

in no way am I suggesting you refrain from commenting. nor am I claiming that your proposed synthetic route is bunk. You didn’t come close to providing enough information for me to draw that conclusion.


So who has done this



still waiting for @DrJosh to tell us if he has.

doesn’t seem like it…
can’t see it being worth the effort.


I asked because I recently witnessed an instagram shouting match where one guy said “I bet you can’t recarb!” Which led me to believe he can…

I think hes the owner of steep hill labs?



It’s beyond my skill level, and seems like success would only be good for bragging rights, but I’d put my money on it being possible to at least some extent.

As a geneticist, I’d also bet money that I could achieve an enzymatic re-carb if I mutagenised and selected.


Theres a chemist lurking around here that has successfully recarbed both CBDa and THCa but he’s being slippery about sharing the Tek… It is 100% possible, but also way above my head


Efficiency? Yield? Know anything more about it?



Damn that was good read!


Has anyone tried formylating THC using HMTA in TFA? I have used this on naphthols and phenols to install aldehydes. A subsequent Pinnick oxidation will yield the carboxylic acid. I know you all are trying to run this in large scales but at a smaller scale this would theoretically work. It doesn’t hurt to try. I am also aware of olefin isomerization under acidic conditions, but proof of concept is more important here.


Dr. Mechoulam did it first in 1969. He carboxylated with Magnesium Methyl Carbonate!divAbstract

Then, in 2011 Nadine Roth at the University of Freiburg in Germany published this paper where she also showed carboxylation of THC-A.

There are two isomers of THC known as THC-A and THC-B. Reactions regarding addition of a carboxylic acid group can be confusing due to the nomenclature here. Also, don’t confuse this with THC-Acetate either :stuck_out_tongue_closed_eyes:

I’m curious to see how regioselective a Kolbe–Schmitt reaction would be when tried with THC.
This paper shows the ortho position being prefered by the -COOH.


Everyone on here knows how to use sci-hub, right?