| Abstract
| - The addition of a 2-silyloxy silylketene acetal to N-benzyl-2,3-O-isopropylidene-d-glyceraldehyde nitrone (Mannich-type reaction) can be stereocontrolled to give 2S,3S,4S and2R,3R,4S adducts as major compounds, depending onwhether the reaction is activated with zinc(II) triflate or tin(IV) chloride, respectively. The corresponding major adductswere used for preparing diastereomeric polyhydroxy-β-aminoesters that were further converted into suitable orthogonally protected enantiomeric d- and l-erythro-sphingosines.
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