carried out the stereoselectivesynthesis of (-)-β-conhydrine and (+)-α-conhydrine, two bioactive α-hydroxyalkyl-substituted piperidines, using the commercially available and inexpensive amino alcohol (S,S)-(+)-pseudoephedrine as chiralauxiliary. The key step of this synthesis relies on new methodology previously developed in our group, consisting of the chemo- and diastereoselective addition of Grignard