Stereoselective allylation reactions of acyclic and chiral α-amino-β-hydroxy aldehydes 3: Total synthesis of (+)-1-epi-castanospermine

Stereoselective allylation reactions of acyclic, chiral α-amino-β-hydroxy aldehydes containing four contiguous stereocenters were conducted. Allylation mediated by MgBr2∙OEt2 afforded the anti-product. A plausible mechanism of the allylation reaction is also described. The resulting allylation product was used for the total synthesis of (+)-1-epi-castanospermine.