Synthesize Selina-4(15),7(11)-diene (CAS #58893-88-2) & selina-3,7(11)-diene (CAS #6813-21-4)

I work for an analytical lab and I constantly see these 2 terpenes show up in large quantities (sometimes representing the 2 top terpenes based on intensity). After corroborating with the literature and confirming them by GCMS with a NIST library, I am positive they are CAS# 58893-88-2 and 6813-21-4. They appear to be isomers of one another. They always show up together and in the same ratio vs. one another (meaning they are always both present together). I can’t find a vendor who supplies these as analytical standards, therefore, they can’t be quantified accurately. Yes, I can theoretically quantify them based on the response of the surrounding terpenes but I would like to actually procure the standard. Any organic chemists have any insight on how to synthesize these? I think the industry needs these 2 compounds identified and quantified as they represent a good portion of the terpene profile.

Thanks.

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Interesting.
When I was working with the analytical chemists that invented the method for TCDD at ppq levels I was always amazed at the number of unquantified peaks I would see in the MS output.
Nature is complicated even at fid sensitivity.

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I wonder if its nutrient based since most of the same staple nutrients are used during the entire plant cycle. While others can be added to alter terp profiles.

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SciFinder and Google Scholar should help you find a synthetic route.

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I don’t know if it’s nutrient based. I see different responses among different strains. I assume it’s strain dependent.

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Very little info on these 2. I requested from Restek and Sigma a quote for a custom order for these 2. Both said they can’t make it. You would think with their resources, they could do something like that.

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Here is another concentrate sample; you can clearly see these 2 compounds represent a large portion of the profile

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I find it hard to believe that a vendor cannot synthesize something nor come up with something on the fly. Here are two reported processes that you can do yourself.

Sequence 0 (1).pdf (34.6 KB)

Sequence 0.pdf (38.7 KB)

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Awesome thanks. I assume it’s because they don’t want to rather than their lack of skill.

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Look into selinenes and eudesmol. You may just need to broaden your search a bit. I think your search may be related to one of my own.

I will follow up later when I get back to my computer but I have a research paper that identifies dozens of volatiles in cannabis. I’ve been compiling a list of terpenoids, flavonoids, alcohols, as I too would love to obtain the isolates. I always found it odd that these two sesquiterpenes have been observed in cannabis in relatively substantial amounts but they are not readily available in isolate form through any supply channels. IIRC they exist in hops oil and a couple other common essential oils, there just may not be a sufficient demand for them.

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Not a demand YET. @MassTerpenes and @Chemist420 about to team up and mass produce a bit? See how it goes? Ill take a sample

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Greetings:

I am a chemist, I attended UCSB, and I still live in Santa Barbara. I have owned several chemical companies, and I develop synthetic methods for synthesis of many types of chemicals, and I have been known to synthesize this and that, in my own lab, or on contract to others in their labs. I am lightly familiar with both of the chemicals you are interested in. Very very briefly, you will note the double bond on 58893 that is a single bond on 6813 and other differences between the two - and though these are both a bit of a numbering nightmare, there are relatively substantial differences, at least in terms of developing a facile synthesis, such that in terms of developing a synthetic procedure if one wanted to synthesize these, one would not synthesize the two from the same precursors but of different isomerism, or develop a single synthesis with a racemate and then attempt to separate isomers with something like tartaric acid, though the plant may be doing something along these lines in some capacities, which might account for your finding them together on a consistent basis. While you are obviously observant and you have fine mental acuity, and are thus wanting to assign logic to patterns in your observations (your running into the two together and never just one or there other), I would suggest that there may be other factors at work that account for your finding both when you find one… Go ahead and contact me by message, and I may be able to help you with a traceable supply of both of these chemicals at a “reasonable” rate, though unfortunately, whenever custom synthesis labs encounter folks that are interested in traceable lots, chains of custody or other “analytical standard language”, when they are estimating prices, there is a knee-jerk response from the lab operator which causes a wrist jerk which moves the decimal on the estimated price one or more places to the right, regardless of whether the difference to the lab is largely limited to a few hours of extra paperwork, which in terms of man hours is insignificant compared to the actual cost of R & D and production and purification. I would also suggest that if you don’t want to contact me for help, that you can and will find suppliers on your own, with a bit of diligent searching, though such labs will likely obtain these from natural sources rather than synthesis, unless you are in need of a relatively large quantity. Pricing on something like these two could easily hit $30K for a kilogram - enabling you to sell the standards to others at grossly inflated prices, such as $100/10mg, making your kilogram worth $10,000,000 if sold as “analytical standards” (think autosampler vials and solvent here for overhead) or the price could go down to $25K for a handful of grams (you are detecting my poking fun at the analytical standards market, which is an enormous ripoff, albeit a “necessary component” of “proper analytical method and testing”… Custom synthesis from reliable labs that understand the paperwork for production of analytical standards and are honest typically do not come cheap, even in these modern times (I am old, and thus remember when custom synthesis was not as much of an everyday things as it is today). But one way or another, you now understand the likely financial aspects of obtaining these by custom synthesis, and the possible aspects of the profitability of your going into the analytical standards business, which I dabble in myself… There are a LOT of cannabinoids for which there are NOT analytical standards… :slight_smile:

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Thanks for the info. At this point, I would take anything with a purity >90%, traceable or not. 250-1000 mg would be plenty. Terpenes are not a required test…yet. Traceable would be best but for R&D purposes, who cares. Although I would wonder about the stability. Most of the terpenes that elute in that area have the same response. I would suspect the same. However, I see so much junk that comes out between b-caryophyllene and a-bisabolol, so that statement may not be true. I would just calculate it and report it, coded to denote it’s unvalidated and theoretical. I just see it so frequently, in particular with concentrate samples that have a low monoterpene profile.

Interesting idea to sell the analytical standard. That is something to look into.

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https://www.sigmaaldrich.com/technical-documents/articles/analytical/food-beverage/cannabis-terpenes-identification-spme-gcms.html

If you look at peak 42, there is a peak right beside it that has been unidentified. This application uses headspace as its injection system. I use a solvent prep with a liquid injection. But having looked through 1000s of terpene samples, our prep always has the response at like a 45:55 ratio of peak 1 to peak 2. So I think I have identified these correctly. And this ratio happens always as such. I will have to dig up the MS Library identification + the mass spectrum.

I do commonly see these at high concentrations in samples where there is less monoterpenes. This doesn’t always hold true, but when I used to smell the sample and look at the chromatogram, this trend seemed to pop up more than not.

Found the MS Data.

Taking this information, the Sigma Paper, and the fact they occur in the same ratio in every sample, makes me believe these are the correct 2 compounds.

Thanks for viewing.

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https://www.uniprot.org/uniprot/B5HDJ6
Some bio synthetic information on one of the compounds

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Beautiful. Thanks.

Are these samples from CRC concentrates?

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Do you think there’s a conversion taking place?