The high-yielding and highly efficient stereoselective synthesis of enantiopure anti,anti and syn,anti acetylenic 2-amino-1,3-diol stereotriads from r-alkoxy-tert-butanesulfinylimines bearing a stereocenter r to the imino group is reported. The stereoselectivity of the reaction of these tert-butanesulfinyl (tBS)-imines with allenylzinc (()-1 was found to be controlled only by the configuration of the tBS group. An excellent kinetic resolution of the racemic allenylzinc species was observed, allowing a high stereocontrol no matter what the configuration or the protecting group of the r-alkoxy group.