D10 degradation products

Would anybody happen to know the degradation products when converting d9-THC to d10? We are seeing a huge peak between d8 and d10 on a C18 column that has a similar UV spectrum to CBC. We are assuming its a degradation product created during the reaction.


Can you share your chromatogram?

The two d10 diastereomers elute at different retention times. Do you have both available standards in your method?


We have the 6aR,9R-d10-THC (CAS 95543-62-7) standard. We see 1 peak when running the standard alone.

Here is a sample chromatogram


It is probably (6aR,9S)-d10-THC.

Your d10 peak possibly contains some d6a,10a-THC.

Here is some data:



Or the (9S) isomer, or both, since they will exhibit identical retention times on an achiral stationary phase.

Or maybe (9R)-d10 more readily converts to the corresponding d6a(10a) structure than the (9S)-d10 diastereomer?


Do you see this same 9S:9R ratio the same in all samples? We have another sample ran that shows a 1:1 ratio of unknown : d10. The chromatogram above is 6:1 unknown : d10

Thank you.

This is dependent on which synthetic strategy you employ. In the classic ‘84 Srebnik paper which I am sure you are following to some extent, one of the reagent systems does indeed favor 9S dramatically, they say 8:1 9S/9R.

Note that the paper uses the older numbering system:


Really appreciate your help. Just ordered the 9S standard.


Great, please update us. You may want to source the two 6a,10a standards, but we’ve only achieved separation between them all on GCMS so far.


Though the diastereomers are very similar, they may not have the same retention times on achiral media. Enantiomers would require chiral media, though my best guess would be that they are identical. 6a is a candidate if the diastereomers don’t coelute though. how much does it occur as a by-product?

Edit: Didn’t realize that 6a was 10a enantiomer, was thinking d7, which is wrong because I am a spoon!

It is almost definitely 6a10a THC. Likely a mixture of the two isomers but more of the R than the S.

I might be able to help out reducing your side products. Send a DM here if you’re interested in a consult


The d6a(10a)-THCs are actually an enantiomeric pair. The 6a-10a double bond removes chirality at the ring junction and the only chiral carbon is #9.

And due to the ring puckering in d6a(10a), it is now the 9S enantiomer which is the more active structure.

To me, that’s the main importance of the diastereomeric d10 pair; it allows access to the respective enantiomers of d6a(10a).

Historically, quite a bit of work went into the development of Parahexyl, a racemic formulation of d6a(10a) with a 6-carbon tail on the resorcinol.


Ohhhhh, didn’t even think about that. The second I start to neglect my IUPAC handbook, it always comes back to kick me.

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Yes, I still remember the day when I realized it myself and you don’t really need a handbook. Molecules with only one chiral center cannot form diastereomers, that’s kind of in the definition.

OK, that unknown peak was the (9S) form. When ordering d10 from Cayman, typing ‘d10-THC’ in the search bar only pulls up the (9R) form standard + 2 JWN molecules. They probably should fix that.

Thanks for all of the help.

Does anybody consume this stuff? Is there a lot of d10 material on the market?


Not very much real d10 in the market. More 6a,10a. Thanks for the update.