To understand stereoisomerism as an organic chem student does, read this."laevo" (l) and "dextro" (d) are an old-fashioned terminology for optical isomers. A "racemate" is a 50:50 mixture of these two (dl). In modern chemical practice, these are referred to by their absolute configurations (S,R). The absolute configuration is much more informational, but I'll stick with the d,l parlance here since all the other alchemists do.
d-methamphetamine is, quantitatively, the stronger meth isomer. References usually describe the dextro-isomer as x- times stronger than the laevo, though I've never heard of anyone getting high on the latter. There is a twist however. I think Uncle Fester put it well. To paraphrase: "I find the racemate to be invigorating, the d-meth more enervating. Also the racemate doesn't have such a negative effect on sexual function." All true, in my opinion.
Here is everything the chemhack really needs to know about these isomers:
- l-ephedrine is chemically reduced to d-methamphetamine.
- d-pseudoephedrine is chemically reduced to d-methamphetamine.
- OTC products contain either l-ephedrine or d-pseudoephedrine.
- The mixture of isomers obtained through extraction of natural ephedra is chemically reduced to a mixture of d-meth, d-amphetamine, and things unknown to me.
Ephedrine vs Pseudoephedrine? They are essentially isomer categories of ephedrine. It's just a matter of pharm labeling. The hydroxyl group (OH) can take one of two physical orientations in its bond with the first chiral carbon. But that hydroxyl is the very one being removed in a reduction, and the H that replaces it can take only one position. So it doesn't matter. What matters is the orientation off the second chiral carbon, and that's how you choose your ephedrine.
Want to experiment with chemical separation of these isomers so you know just what you've got? It's actually quite easy to do that with meth. Read the original patent. Does this work with ephedrine enantiomers? I don't know.
