This is the most easy preparative method. I shouldn't drop numbers since some while has passed since (bit over a decade) But it’s just the preparation of a NaOH aq. Solution to which gamma butyrolactone is then added in portions to just above neutral. With a magnetic stirrer it’s done in less then any prep I know. One of my acolytes who lives away fully designed a procedural synthesis starting from imagination. He converted comercial GABA to GHB via gama diazonium salt which afforded the alcohol group after hydrolysis. It’s in dcm now but the odor is distinct, strong and perceivable with dcm as solvent. It’s not really beginner friendly but success on the first try is quite a thing and the refined method will be posted in some future thread. Get your hands on GBL if possible and with that is hocus-pocus.