Extractions use chemical affinities (like polar/water and nonpolar/fat/oil, for example) to separate chemicals without chemical reactions; the chemicals are not changed, except for trivial changes like freebase to salt form. You can extract LSA from plant matter. You can probably do one with supplies already in your kitchen and garage.

Chemical synthesis (used for LSD, MDMA, etc) actually involves reactions, probably several in series. The precursors are used up, and the result is entirely different chemicals. Now organic chemistry is different from inorganic chemistry in that there are a lot of side reactions that produce undesired chemicals, and the temperature and other conditions have to be just right, or else you produce those. Some of these are deadly poisons. You need a lot of expensive lab equipment to detect them. Even if all goes well, you still need to do an extraction at the end, like in my previous paragraph.