So a major source of information is Breaking Bad, A series where the protagonist tried to dissolve a body in one of the weakest but most toxic mineral acids Hydrofluoric acid. YMMV on that one.
G-Chem you are correct, there are several ways to P2P from l-meth and also from pseudophedrine/ephedrine and there are also ways to racemize l-meth into d/l racemic meth and then resolve again. It has to be pointed out though that if chiral meth is the objective then starting from chiral ephedrine or pseudoephedrine is cheaper and easier and ephedrine/pseudoephedrine is readily available.
Chiral (enantiopure) meth can be made from P2P using chiral alphamethylbenzylamine as the amine or using chiral reductive amination or even chiral reduction to a chiral alcohol, of course there are other more indirect ways and other chiral amines which would be obvious to someone skilled in the art.
In those situations the chirality is coming from the chiral reducing agent or a chiral amine, something else (which by definition is chiral itself) is providing and transferring the chirality.
This is an important concept to grasp, it is actually a key idea. Making racemic and the separating the two enantiomers as diasteriomeric salts for example is not transfer of chirality from a chiral synthetic starting material, instead the tartaric acid in a resolution step is chiral and that provides chirality to the diastereomeric salt pair, because diastereomers have different physical properties, one diastereomer can then be separated from its mirror image.
Draculic acid look up N-Nitrosoamines for the answer to what happens if you hit secondary amines with acidified sodium nitrite in effect HONO. basic stuff.
Terminology is important, to understand what people are saying you need to be speaking the same language. this is the generally accepted use of one pot,
One pot does not have anything to do with whether stuff is distilled or not, one pot is where sequential reactions are carried out in one vessel (hence being called one pot) whether it is a glass lined reactor or a coke bottle.
With or without isolation of the intermediate products in that pot. so for example react step 1 crash solid intermediate product decant liquid, wash add new reagents react step 2 is a one pot with isolation, a one pot 2 step reaction.
Telescoped reactions are sequential reactions where the product is carried into the next step without purification to remove by products from the earlier step.
There is absolutely nothing wrong with one pot or telescoped reactions they are used all the time in Pharma API manufacturing because often they result in higher yields than more traditional approaches, they also prevent worker exposure to intermediates. In Pharma though the chemists actually know and understand the chemistry, the by-products and carefully manage the whole scheme.
On the original topic chiral PMK glycidate to chiral MDMA requires chirality transfer from the PMK glycidate to the product and to remain chiral that position basically it needs to remain tetrahedral, sp3 hybridized. If the chirality is not transferred from the PMK glycidate then it is irrelevent whether the starting glycidate is chiral or not.
Perhaps we need to wait for Clubcard to explain the mechanism of the fantastic(al) chiral PMK glycidate to chiral MDMA route.
this is most likely remains a total red herring because commercial Ethyl Chloropropionate (and Methyl) most certainly is not all enantiopure some is some isn't. if racemic ethyl chloropropionate is used in a Darzens reaction to make PMK glycidate then the glycidate is also racemic.
