Synth of Ephedrine from protected Cyanohydrins
(Rated as: excellent)
Stereoselectrive Syntheses of Ephedrine and Related 2-Aminoalcohols of High Optical Purity from Protected Cyanohydrins
Jackson et al
Tetrahedron Letters, 31, 10, 1447-1450 (1990) (http://chemistry.mdma.ch/hiveboard/rhodium/pdf /ephedrine.gr
Ephedrine and related optically active b-aminoalcohols can be prepared by zinc borohydride reduction of aryl O-protected magnesium imines and aryl a-hydroxyimimes which in turn are readily available from optically active cyanohydrins.
Saludos, from Latin america