1850-88-0Relevant academic research and scientific papers
Catalytic asymmetric addition of diethylzinc to aldehydes via chiral, non-racemic β-hydroxy and β-methoxy salicylhydrazone catalysts
Banerjee, Sucharita,Ferrence, Gregory M.,Hitchcock, Shawn R.
experimental part, p. 837 - 845 (2010/11/02)
(1S,2S)-Pseudoephedrine and (1S,2S)-pseudonorephedrine have been converted to their corresponding hydrazines and condensed with either o-salicylaldehyde or 2-hydroxy-1-naphthaldehyde to afford a series of β- hydroxysalicylhydrazones that have been employed in the asymmetric addition of diethylzinc to 2-naphthaldehyde in up to 56% ee. In addition to this, the Ephedra hydrazines were also condensed with the o-hydroxyacetophenone derivative to form related hydrazones. The use of these corresponding hydrazones in the asymmetric addition reaction with the diethylzinc did not yield improved enantioselectivities. Finally, Enders' hydrazine was used as a chiral scaffold for the synthesis of β-methoxysalicylhydrazones. These compounds were employed in the asymmetric addition of diethylzinc to a variety of aromatic aldehydes with enantiomeric excesses as high as 68% ee.
X-ray crystallographic and 13C nuclear magnetic resonance studies of 3,4,5,6-tetrahydro-2H-1,3,4-oxadiazin-2-ones derived from ephedrine and pseudoephedrine
Hitchcock, Shawn R,Nora, George P,Casper, David M,Squire, Michael D,Maroules, Christopher D,Ferrence, Gregory M,Szczepura, Lisa F,Standard, Jean M
, p. 9789 - 9798 (2007/10/03)
3,4,5,6-Tetrahydro-2H-1,3,4-oxadiazin-2-ones derived from (1R,2S)-ephedrine and (1S,2S)-pseudoephedrine have been synthesized and their conformational properties have been examined. The ephedrine heterocycles 5-7a appear to favor one set of equilibrating
