mixing LSD xtals

[Ballz_Trippington]

Yup just the one.

 

[DroneLore]

Yup just the one.

So have all synths always been able to produce the active stereoisomer and isolate it? It was my understand that separating racemic mixtures is extremely difficult, even with the technology available to chemists today, let alone 40 years ago. Is it possible that the differences in batches may be due to different ratios of stereoisomers?

 

[Ballz_Trippington]

All this was addressed in this very thread if you bothered to read it...
Separating the isomers via chromatography is actually the last step in LSD synthesis... yiu should read a few posts above .

 

[DroneLore]

All this was addressed in this very thread if you bothered to read it...
Separating the isomers via chromatography is actually the last step in LSD synthesis... yiu should read a few posts above .

I see mention of iso-LSD, but no mention of (+)LSD or (-)LSD. I did read the whole thread, by the way.

http://upload.wikimedia.org/wikiped...ide_stereoisomers_structural_formulae_v.2.png

What is the process for separating (+)LSD and (-)LSD? There was brief mention of a chiral substrate, which I could see being able to separate the two.

Edit: Unless the syntheses are done such that no (-)LSD is formed. In that case, obviously, one would not need to worry about separating the two. That was my original question: Are LSD synths stereoselective, as in they do not produce all possible enantiomers to begin with?

 

[Sir Ron Pib]

Blind studies would be a very expensive way to go about something when you can do chemical analysis to see if there is even the possibility of need to do such a study unless we are going to suggest actual magic property in which case you don’t need tyo bother with science “which doesn’t know everything” as people say when there isn’t a scrap of evidence for something - LSD is nearly at the top of the lysergamide potency till proved otherwise (ETH-LADs slightly stronger) - hypothesising things that would likely need to be way more active just seems to be going to the sorts of extremes of increasing complexity some conspiracists go to - all to back up unlikely and dicey subjective reports and we do have a wealth of research on psychology of placebo nocebo suggestability subjective experience and the like - I’ll grant some difference isn’t entirely impossible though I think most now discount it as mumbo jumbo and really it’s just a matter of applying occum razor - Owsley did blind tests in the 60s - the same acid gave reported different effects based on pill colour - just what we would expect from what we now of peceptual psychology esp in relation to food and medicine. Totally skeptical unless something better than what I have heard over the last few decades comes up

 

[sekio]

Edit: Unless the syntheses are done such that no (-)LSD is formed. In that case, obviously, one would not need to worry about separating the two. That was my original question: Are LSD synths stereoselective, as in they do not produce all possible enantiomers to begin with?

If you start with ergotamine or biologically-derived lysergic acid, that material is chirally pure and you'll end up making only D-LSD and D-iso-LSD. Unlike the 8' position (iso <--> non-iso) you can't interconvert D- and L- LSD. Nobody undergoes total synthesis of LSD because it'd take too many damn steps for a 0.1% yield either.

The alumina column chromatography will seperate the iso-LSD from D-LSD and you should be left with chirally pure D-LSD at the end of a synthesis. No chiral chromatography is ever needed. Go watch The Sunshine Makers and pay attention to Scully's flowchart he draws... there's no chiral stuff anywhere. You take lysergic acid, pop an amide on there, and then seperate iso<-->non-iso. And even still, the modern method used in TiHKAL is even better....

Also, readign about the early acid cooks in the '60s and '70s... in the past peoiple have distributed the same LSD with different colored dyes in them and people were convinced the different colors had varying psychological effects, despite the fact it was all LSD at the same dilution. Goes to show how subjective the experience can be!

 

[Solipsis]

I see mention of iso-LSD, but no mention of (+)LSD or (-)LSD. I did read the whole thread, by the way.

http://upload.wikimedia.org/wikiped...ide_stereoisomers_structural_formulae_v.2.png

What is the process for separating (+)LSD and (-)LSD? There was brief mention of a chiral substrate, which I could see being able to separate the two.

Edit: Unless the syntheses are done such that no (-)LSD is formed. In that case, obviously, one would not need to worry about separating the two. That was my original question: Are LSD synths stereoselective, as in they do not produce all possible enantiomers to begin with?

iso-LSD has an inverted chiral center that partially changes the structure and makes it inactive, because it is only part that changes, there is not a completely inverted stereoisomer that IS active. (+) and (-) are dextro and levo LSD. There is no need to separate them, there is need for it because only one is active and the other is not a bother. To answer the question, usually racemic mixtures like that are resolved with optically pure tartaric acid to use the different tendencies to crystallize with the stereoisomer products to separate.

Not sure if I see much difference with doing that resolution on ergotamine before the synthesis unless that has favorable differences in crystallization that make it much easier to separate than the finished LSD. A reason may be that it is more ideal to get it done before proceeding, as you would want to limit all such processing and if some of the precursor degrades while doing this you will get it out with the zeolite chromatography later.
A more farfetched reason might be that it makes the amounts you end up with 2 times smaller so less illegal, but seems like a pretty bad reason since large amounts of LSD are so extremely illegal anyway.

I don't think they make it optically pure.