<unk>  is a diastereomer of ephedrine and is readily reduced into methamphetamine or oxidized into methcathinone. Two pairs of enantiomers: ephedrine (top) and<unk>  (bottom) Nomenclatures The dextrorotary (+)- or d- enantiomer is (1S,2S)-pseudoephedrine, whereas the levorotating (−)- or l- form is (1R,2R)-pseudoephedrine. In the outdated system (+)-pseudoephedrine is also referred to as<unk>  and (−)-pseudoephedrine as<unk>  (in the Fisher projection then the phenyl ring is drawn at bottom). Often the system (with small caps) and the d/l system (with lower-case) are confused. The result is that the dextrorotary d-pseudoephedrine is wrongly named<unk>  and the levorotary l-ephedrine (the diastereomer) wrongly ephedrine. The IUPAC names of the two enantiomers are (1S,2S)- respectively (1R,2R)-2-methylamino-1-phenylpropan-1-ol. Synonyms for both are psi-ephedrine and threo-ephedrine.<unk>  is the International Nonproprietary Name of the (+)-form, when used as pharmaceutical substance.
Pseudoephedrine
Ephedrine
Theobromine
Tesofensine
Benzoctamine
Bethanechol
Butalbital
Guaifenesin