STUDY ON CONVERSION OF L(+)-Ψ-EPHEDRINE INTO L(-)-EPHEDRINE(Ⅰ)

L(-)-Ephedrine hydrochloride was obtained from L(+)-Ψ-ephedrine by the following steps: L(+)-N-acetyl-Ψ-ephedrine was first prepared by acetylation of L(+)-Ψ-epbedrine, the product was then dissolved in glacial acetic acid to form a 5% solution and refluxed for one and one half hour. The acetic acid was re- covered immediately from the mixture. The product was hydrolyzed with 10% NaOH and finally converted to its hydrochloride. The yield was about 81-85% of the theoretical based on the L(+)-N-acetyl-Ψ-ephedrine. Under the same conditions only about 24% L(-)-ephedrine could be converted to L(+)-Ψ-ephedrine.