Reactions of (-)-Ephedrine, (+)-Norpseudoephedrine and Derivatives with N,N-Dimethylacetamid-dimethylacetal and N,N-Dimethylformamid-dimethylacetal

Article abstract of DOI:10.1007/BF00811546

The reactivity of (-)-ephedrine (2) and (+)-norpseudoephedrine (3) towards the amid-acetals 1 a/b has been studied.Both 2 and 3 were acetylated resp. formylated at first at the amino group.Nevertheless, derivatives of 2 and 3 possessing a trisubstituted amino group react with 1 a in a <3.3> sigmatropic rearrangement to ortho substituted dimethylcarbamoylmethyl derivatives.By subsequent reduction with lithiumaluminiumhydride the aromatic compounds 8, 13, and 18 with two aminoethyl groups are easily available.In contrast to these results 1 b did not furnish any rearrangement products. Keywords. (-)-Ephedrine; (+)-Norpseudoephedrine; N,N-Dimethylacetamid-dimethylacetal; N,N-Dimethylformamid-dimethylacetal; Sympathomimetic effects; Sigmatropic rearrangements.