Stereo- and Enantioselective Synthesis of Acetylenic 2-Amino-1,3-diol Stereotriads

The high-yielding and highly efficient stereoselective synthesis of enantiopure anti, anti and syn,anti acetylenic 2-amino-1,3-diol stereotriads from alpha-alkoxy-tert-butanesulfinylimines bearing a stereocenter alpha 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 alpha-alkoxy group.